Trending March 2024 # Types Of Xml Parsers With Examples # Suggested April 2024 # Top 8 Popular

You are reading the article Types Of Xml Parsers With Examples updated in March 2024 on the website Hatcungthantuong.com. We hope that the information we have shared is helpful to you. If you find the content interesting and meaningful, please share it with your friends and continue to follow and support us for the latest updates. Suggested April 2024 Types Of Xml Parsers With Examples

Definition of XML Parsers How does XML Parsers Work?

Fig: XML parser Process

The Parser could be categorized as validating and non- validating

Validating Parser: It needs a Document type Declaration to parse and gives an error if the respective document doesn’t match with DTD and constraints.

Non-Validating: This Parser eliminates DTD and the parser checks for the well-formed document.

Types of XML Parsers with Examples

This section talks about various types of parsers used recently in parsing XML document. They are:

DOM Parser

SAX Parser

JDOM Parser

stAX Parser

Xpath Parser

The most important type is DOM and SAX which is explained detail in this article.

1. DOM Parser (Tree-Based)

Document Object Model is a W3C Standard and converts the XML document which is to parsed into a collection of objects and uses DOM API. It consists of a collection of nodes and is associated with other nodes in the tree. DOM is much easier to use as sorting and searching process is made chúng tôi DOM parser the content of the XML file is modified with Node and Node List. The Steps involved in Parsing with java:

Getting document builder objects

Taking XML document as input, parseit and return the class.

Getting values of the input id through attributes and sub-elements.

Display the results.

First is the XML file that generates the values which are going to be parse and java objects are constructed automatically.

Example

chúng tôi

Read.java

}

And here is the Output is shown for the XML File. Save XML and java file in the same folder during execution. In this article I have used java-jdk- 13.0.1 using command prompt. Save the respective folder in any drive and do the set path.

Output:

2. SAX Parser

SAX Is Simple API for XML and meant has Push Parseralso considered to be stream-oriented XML Parser. it is used in case of high- performance applications like where the XML file is too largeand comes with the community- based standard and requires less memory. The main task is to read the XML file and creates an event to do call functionor uses call back routines. The working of this parser is just like Event handler part of the java. it is necessary to register the handlers to parse the document for handing different events. SAX Parser uses three methods startElement() , endElement() , characters().

startElement(): Is used to identify the element, start element is identified.

endElement(): To stop the Supermarket tag in the example.

character(): Is used to identify the character in the node

The xml file is the same file used in DOM Parser chúng tôi and next step generate chúng tôi file

Example

Rsax.java

}

Output:

Conclusion

Therefore, we have discovered how to use XML parsers in Java with the powerful APIs in the applications.Also, we have seen the implementation of two parsers using java. When compared with DOM,sax parser uses arbitrary size to parse whereas DOM requires available memory to load the complete chúng tôi Parsers differs based on the performance.

Recommended Articles

This is a guide to XML Parsers. Here we also discuss how does xml parsers work? along with examples and its code implementation. You may also have a look at the following articles to learn more –

You're reading Types Of Xml Parsers With Examples

Oracle Pl/Sql Object Types Tutorial With Examples

What is Object Type in PL/SQL?

Object-Oriented Programming is especially suited for building reusable components and complex applications. They are organized around “objects” rather than “actions” i.e. the programs are designed to work and interact with the entire object rather than the single action. This concept allows the programmer to populate and manipulate the details at object entities level.

Below picture depicts an example of the object type in which a bank account is considered an object entity. The object attributes include things which are holding some attribute values, for example in Bank Account; it is Account number, bank balance, etc. while object methods describe the things like calculating interest rate, generating bank statement, etc. which requires certain process to be completed.

In PL/SQL object-oriented programming is based on object types.

An object type can represent any real-world entity. We are going to discuss more object types in this chapter.

In this tutorial – you will learn,

Components of Object Types

PL/SQL object type contains mainly two components.

Attributes

Members/Methods

Attributes

Attributes are the column or field in which data are stored. Each attribute will be mapped to the datatype that defines the processing and storage type for that attribute. The attribute can be of any valid PL/SQL datatype, or it can be of another object type.

Members/Methods

Members or Methods are subprograms that is defined in the object type. They are not used to store any data. They are mainly used to define process inside the object type. For examples validating data before populating the object type. They are declared in the object type section and defined in the object type body section of the object type. Body section in object type is an optional part. If no members are present, then an object type will contain no body part.

Create Object in Oracle

An Object type cannot be created at subprogram level, They can be created only at the schema level. Once the object type is defined in the schema, then the same can be used in subprograms. The object type can be created using ‘CREATE TYPE’. The type body can be created only after creating its object type.

( . . ); / ( IS BEGIN END;‭ . . ‬ ); /

Syntax Explanation:

The above syntax shows the creation of ‘OBJECT’ with attributes and ‘OBJECT-BODY’ with methods.

The methods can also be overloaded in the object body.

Declaration Initialization of Object Type

Like other components in PL/SQL, object types are also needed to be declared before using them in the program.

Once the object type is created it can be used in subprogram declarative section to declare a variable of that object type.

Whenever any variable is declared in the subprogram as object type, at run-time a new instance of the object type will be created, and this newly created instance can be referred to the variable name. By this way, a single object type can store multiple values under different instances.

DECLARE BEGIN . . END; /

Syntax Explanation:

The above syntax shows the declaration of a variable as an object type in the declarative section.

Once the variable is declared as an object type in a subprogram, it will be atomically null i.e. the entire object itself a null. It needs to be initialized with values to use them in the program. They can be initialized using constructors.

Constructors are the implicit method of an object that can be referred with the same name as that of the object type. The below syntax shows the initialization of the object type.

DECLARE BEGIN END; /

Syntax Explanation:

The above syntax shows the initialization of the object type instance with a null value.

Now the object itself is not null as it has been initialized, but the attributes inside the object will be null as we have not assigned any values to these attributes.

Constructors

Constructors are the implicit method of an object that can be referred with the same name as that of the object type. Whenever the object is referred for the first time, this constructor will be called implicitly.

We can also initialize the objects using these constructor. The constructor can be defined explicitly by defining the member in object type body with the same name of the object type.

Example 1: In the following example we are going to use the object type member to insert the record into emp table with values (‘RRR’, 1005, 20000, 1000) and (‘PPP’, 1006, 20000, 1001). Once the data is inserted, we are going to display the same using object type member. We are also going to use the explicit constructor to populate the manager id by default with 1001 value for the second record.

We are going to execute it in below steps.

Step1:

Create Object type

Object type body

Step2: Creating an anonymous block to call created object type through implicit constructor for emp_no 1005.

Step3: Creating an anonymous block to call created object type through explicit constructor for emp_no 1006.

Step 1) Create Object type and Object type body

CREATE TYPE emp_object AS OBJECT( emp_no NUMBER, emp_name VARCHAR2(50), salary NUMBER, manager NUMBER, CONSTRUCTOR FUNCTION emp_object(p_emp_no NUMBER, p_emp_name VARCHAR2, p_salary NUMBER) RETURN SELF AS RESULT), MEMBER PROCEDURE insert_records, MEMBER PROCEDURE display_records); /

CREATE OR REPLACE TYPE BODY emp_object AS CONSTRUCTOR FUNCTION emp_object(p_emp_no NUMBER,p_emp_name VARCHAR2, p_salary NUMBER) RETURN SELF AS RESULT IS BEGIN Dbms_output.put_line(’Constructor fired..'); SELF.emp_name:=p_emp_name; SELF.salary:=p_salary; SELF.managerial:=1001; RETURN; END: MEMBER PROCEDURE insert_records IS BEGIN INSERT INTO emp VALUES(emp_noemp_name,salary,manager); END MEMBER PROCEDURE display_records IS BEGIN END: END: /

Code Explanation

Code line 1-9: Creating the ’emp_object’ object type with 4 attributes and 3 members. It contains the definition of constructors with only 3 parameters. (Actual implicit constructor will contain the number of parameters equal to the number of attributes present in the object type)

Code line 10: Creating the type body.

Code line 11-21: Defining the explicit constructor. Assigning the parameter value to the attributes and assigning the value for attribute ‘manager’ with the default value ‘1001’.

Code line 22-26: Defining the member ‘insert_records’ in which the attributes values are inserted into ’emp’ table.

Code line 27-34: Defining the member ‘display_records’ in which displaying the values of the object type attributes.

Output

Type created

Type body created

Step 2) Creating anonymous block to call created object type through implicit constructor for emp_no 1005

DECLARE guru_emp_det emp_object; BEGIN guru_emp_det:=emp_object(1005,’RRR',20000,1000); guru_emp_det.display_records; guru_emp_det.insert_records; COMMIT; END;

Code Explanation

Code line 37-45: Inserting the records using the implicit constructor. Call to constructor contains the actual number of attributes values.

Code line 38: Declares the guru_emp_det as object type of ’emp_object’.

Code line 41: Statement ‘guru_emp_det.display_records’ called the ‘diplay_records’ member function and the attributes values are displayed

Code line 42: Statement ‘guru_emp_det.insert_records’ called the ‘insert_records’ member function and the attributes values are inserted into the table.

Output

Employee Name: RRR

Employee Number: 1005

Salary: 20000

Manager : 1000

Step 3) Creating anonymous block to call created object type through explicit constructor for emp_no 1006

DECLARE guru_emp_det emp_object; BEGIN guru_emp_det:=emp_object(1006,'PPP',20000); guru_emp_det.display_records; guru_emp_det.insert_records; COMMIT; END; /

Output

Employee Name:PPP Employee Number:1006 Salary:20000 Manager:1001

Code Explanation:

Code line 46-53: Inserting the records using the explicit constructor.

Code line 46: Declares the guru_emp_det as object type of ’emp_object’.

Code line 50: Statement ‘guru_emp_det.display_records’ called the ‘display_records’ member function and the attributes values are displayed

Code line 51: Statement ‘guru_emp_det.insert_records’ called the ‘insert_records’ member function and the attributes values are inserted into the table.

Inheritance in Object Type

Inheritance property allows the sub-object type to access all the attribute and members of the super object type or parent object type.

The sub-object type is called inherited object type, and the super object type is called parent object type. The below syntax shows the how to create parent and inherited object type.

( . . )NOT FINAL; /

Syntax Explanation:

The above syntax show the creation of SUPER type.

( . ); /

Syntax Explanation:

The above syntax shows creation of SUB type. It contains all the members and attributes from the parent object type.

Example1: In the below example, we are going to use the inheritance property to insert the record with manager id as ‘1002’ for the following record (‘RRR’, 1007, 20000).

We are going to execute the above program in the following steps

Step1: Create SUPER type.

Step2: Create SUB type and body.

Step3: Creating an anonymous block to call the SUB type.

Step 1) Create SUPER type or Parent type.

CREATE TYPE emp_object AS OBJECT( emp_no NUMBER, emp_name VARCHAR2(50), salary NUMBER, manager NUMBER, CONSTRUCTOR FUNCTION emp_object(p_emp_no NUMBER,p_emp_name VARCHAR2(50), p_salary NUMBER)RETURN SELF AS RESULT), MEMBER PROCEDURE insert_records, MEMBER PROCEDURE display_records)NOT FINAL; /

Code Explanation:

Code line 1-9: Creating the ’emp_object’ object type with 4 attributes and 3 members. It contains the definition of constructors with only 3 parameters. It has been declared as ‘NOT FINAL’ so it is parent type.

Step 2) Create SUB type under SUPER type.

CREATE OR REPLACE TYPE sub_emp_object UNDER emp_object (default_manager NUMBER,MEMBER PROCEDURE insert_default_mgr); / CREATE OR REPLACE TYPE BODY sub_emp_object AS MEMBER PROCEDURE insert_default_mgr IS BEGIN INSERT INTO emp VALUES(emp_no,emp_name:salary,manager): END; END; /

Code Explanation:

Code line 10-13: Creating the sub_emp_object as inherited type with additional one attribute ‘default_manager’ and member procedure declaration.

Code line 14: Creating the body for the inherited object type.

Code line 16-21: Defining the member procedure which is inserting the records into “emp” table with the values from ‘SUPER’ object type, except for manager value. For manager value, it is using the ‘default_manager’ from ‘SUB’ type.

Step 3) Creating anonymous block to call the SUB type

DECLARE guru_emp_det sub_emp_object; BEGIN guru_emp_det:= sub_emp_object(1007,'RRR',20000,1000,1002); guru_emp_det.insert_default_mgr; COMMIT; END; /

Code Explanation:

Code line 25: Declaring ‘guru_emp_det’ as ‘sub_emp_object’ type.

Code line 27: Initializing the object with the implicit constructor. The constructor is having 5 parameters (4 attributes from PARENT type and 2 attributes from SUB type). The last parameter (1002)defines the value for default_manager attribute

Code line 28: Calling the member ‘insert_default_mgr’ to insert the records with the default manager id passed in the constructor.

Equality of PL/SQL Objects

The object instance that belongs to the same objects can be compared for equality. For this, we need to have the special method in the object type called ‘ORDER’ method.

This ‘ORDER’ method should be the function that returns numerical type. It takes two parameters as input, (first parameter: id of the self-object instance, second parameter: id of another object instance).

The id of the two object instance is compared, and the result is returned in numerical.

Positive value represents that the SELF object instance is greater than another instance.

Negative value represents that the SELF object instance is lesser than another instance.

Zero represents that the SELF object instance is equal to another instance.

If any of the instances is null, then this function will return null.

( RETURN INTEGER IS BEGIN RETURN -1; --any negative number will do RETURN 1; —any positive number will do ELSE RETURN 0; END IF; END; . . ); /

Syntax Explanation:

The above syntax shows the ORDER function that needs to be included in the type body for equality check.

The parameter for this function should be an instance of the same object type.

The above function can be called as “obj_instance_1.match(obj_instance_2)” and this expression will return the numerical value as shown, where obj_instance_1 and obj_instance_2 are the instance of object_type_name.

Example1: In the following example we are going to see how to compare two objects. We are going to create two instances and we are going to compare attribute ‘salary’ between them. We are going to do int two steps.

Step 1: Creating the Object type and body.

Step 2: Creating the anonymous block to call compare the object instance.

Step 1) Creating the Object type and body.

CREATE TYPE emp_object_equality AS OBJECT( salary NUMBER, ORDER MEMBER FUNCTION equals(c emp_object_equality)RETURN INTEGER); / CREATE TYPE BODY emp_object_equality AS ORDER MEMBER FUNCTION equals(c emp_object_equality)RETURN INTEGER IS BEGIN‭ ‬ IF salary<c.salary THEN RETURN -1; THEN RETURN 1; ELSE RETURN 0; END IF:‭ ‬ END; END; /

Code Explanation:

Code line 1-4: Creating the ’emp_object_equality’ object type with 1 attributes and 1 member.

Code line 6-16: Defining the ORDER function which compares the ‘salary’ attribute of SELF instance and parameter instance type. It returns negative if SELF salary is lesser or positive if SELF salary is greater and 0 if salaries are equal.

Code Output:

Type created

Step 2) Creating the anonymous block to call compare the object instance.

DECLARE l_obj_l emp_object_equality; l_obj_2 emp_object_equality; BEGIN l_obj_l:=emp_object_equality(15000); l_obj_2:=emp_object_equality(17000); THEN Dbms_output.put_line(’Salary of first instance is greater’): ELSIF l_obj_l.equalS(l_obj_2)<0 THEN Dbms_output.put_line(’Salary of second instance is greater’); ELSE Dbms_output.put_line(’Salaries are equal’); END IF; END; /

Output

Salary of second instance is greater

Code Explanation:

Code line 20: Declaring the l_obj_1 of emp_object_equality type.

Code line 21: Declaring the l_obj_2 of emp_object_equality type.

Code line 23: Initializing l_obj_1 with salary value as ‘15000’

Code line 24: Initializing l_obj_1 with salary value as ‘17000’

Code line 25-33: Print the message based on the return number from the ORDER function.

Summary

In this chapter, we have seen the object type and their properties. We have also discussed about Constructors, Members, Attributes, Inheritance and Equality in PL/SQL objects.

List Of Xml Commands With Tips & Tricks

Introduction to XML Commands

Web development, programming languages, Software testing & others

Basic XML Commands

The basic XML Commands are as follows.

XML declaration

Element tag: Element names are case-sensitive, and they should start with a letter or underscore. It cannot contain spaces, but they can contain a letter, digits, underscore.

Syntax:

Example:

Root tag: It can be only one in an XML document or XML file.

Syntax:

Example:

Add: Include the node to XML Commands.

Example:

Remove: Used for removing a node the specific id from resulting XML.

SET: This changes the parent element in the resulting XML

Example:

Setattribute: Changes the set of attributes for the parent xml in the resulting XML.

Example:

Empty tag: Command is used to show the element which is not having content.

Example:

Namespace: This is being used to avoid conflict; start the name using a prefix.

Syntax / example:

XLink: This is used to create hyperlinks with in XML documents.

Syntax:

Advanced XML Commands

XML DTD: This is the file that has a DOCTYPE declaration in the XML Commands file. It is used for XML to make it well managed and valid for the XML.

Example:

XML schema: This XML commands is used as XS in the XML file. It also defines the structure of the XML file or the document. It is valid against the schema to be well-formed and valid.

Example:

Xpath: This expression is used to select the root element like /abc, and it selects the other elements based on the tag provided like /abc/1.

To format the XML document, XSL-FO language is being used; it is the set of language that can transform XML into XHTML, filter, and sort XML data. It helps in displaying the negative number and XML data output in the form of pictures and paper.

The XML file looks like as below:

XML can be used for programming as well, to parse the XML based on the java programming document object model is used. It also called a DOM compliant parser. There are many other parsers also available for the same.

XML is also being used with CSS, the same way HTML has been used with CSS. Need to provide the below text in an XML file

XML files can be viewed in internet explorer or other browsers as the HTML pages are viewed while browsing.

Tips and Tricks to use XML Commands

Identify the elements and write in a similar format across all the XML file

To be price while writing a name for tags as they are case sensitive.

The syntax should be well managed.

Always try to use different names; otherwise, conflicts make the XML file unreadable.

The definition of elements and syntax should be clear.

Conclusion

They are easy to write and use for different application while storing and transporting the data. It is lightweight and mainly used in a configuration file of almost in each tool. It is very easy to learn, and all the things are mainly covered in tags. XML validator is being used to validate the XML to manage the file’s format and output or resulting XML.

Recommended Articles

We hope that this EDUCBA information on “XML Commands” was beneficial to you. You can view EDUCBA’s recommended articles for more information.

Definition, Types, Precedence And Examples

What are Operators in C?

The C programming language utilizes operators as symbols representing precise operations to be executed on one or more operands. C provides a wide range of operators that can perform arithmetic, logical, and bitwise operations and operations on pointers and arrays. Operators are symbols that help in performing functions of mathematical and logical nature. The classification of C operators is as follows:

Arithmetic

Relational

Logical

Bitwise

Assignment

Conditional

Special

Even though there are many operators, the execution of these operations happens based on the precedence given to them. Precedence is the order in which the compiler executes the code comprising numerous operators.

Start Your Free Software Development Course

Web development, programming languages, Software testing & others

Explanation of Operators in C

Below is a detailed explanation of operators in C:

#1 Arithmetic Operators

These operators are responsible for performing arithmetic or mathematical operations like addition (+), subtraction (-), multiplication (*), division (/), the remainder of the division (%), increment (++), and decrement (–).

There are two types of arithmetic operators:

Unary Operators: This type of operator works with a single value (operand) like ++ and –.

Binary Operators: This type of operator works with two operands like +,-,*,/

Here is a tabular form of the number of arithmetic operators in C with the functions they perform.

Operator Function

+ Adds two values

– Subtract a second value from the first.

* Multiply two values

/ Divide numerator by the denominator

% Remainder of division

++ Increment operator – increases integer value by one.

— Decrement operator – decreases integer value by one

int main() { int a = 12, b = 6, c; c = a + b; printf(“a+b = %d n”, c); c = a – b; printf(“a-b = %d n”, c); c = a *b; printf(“a*b = %d n”, c); c = a / b; printf(“a/b = %d n”, c); c = a % b; printf(“Remainder when a divided by b = %d n”, c); return 0; }

Output:

#2 Relational Operators

The below table lists the relational operators in C with their functions.

Operator Function Example

== It will check if the two operands are equal 6 == 2 returns 0

!= It will check if the two operands are not equal. 6 != 2 returns 1

> It will check if the operand on the left is greater than the operand on the right

< It will check if the operand on the left is smaller than the right operand 6 < 2 returns 0

>= It will check if the left operand is greater than or equal to the right operand

<= It will check if the operand on the left is smaller than or equal to the right operand 6 <= 2 return 0

Example: C Program using relational operators

int main() { int a = 7, b = 7, c = 10; printf(“%d == %d = %d n”, a, b, a == b); printf(“%d == %d = %d n”, a, c, a == c); printf(“%d < %d = %d n”, a, b, a < b); printf(“%d < %d = %d n”, a, c, a < c); printf(“%d != %d = %d n”, a, b, a != b); printf(“%d != %d = %d n”, a, c, a != c); printf(“%d <= %d = %d n”, a, b, a <= b); printf(“%d <= %d = %d n”, a, c, a <= c); return 0; }

Output:

#3 Logical Operators

Logical Operators are to get True or False results.

The table below lists the logical operators used in C

Operator Function Example (if a=1 and b=0)

&& Logical AND (a && b) is false

|| Logical OR

! Logical NOT (!a) is false

Example: C Program using logical operators.

int main() { int a = 8, b = 8, c = 12, result; result = (a == b) && (c < b); printf(“(a == b) && (c < b) equals to %d n”, result); result = !(a != b); printf(“!(a == b) equals to %d n”, result); result = !(a == b); printf(“!(a == b) equals to %d n”, result); return 0; }

Output:

#4 Bitwise Operators

These operators are for bit-level operations on the operands. The operators first convert into bit-level and then perform the calculations.

Operator Function

& Bitwise AND

| Bitwise OR

^ Bitwise exclusive OR

~ Bitwise complement

<< Shift left

>> Shift right

Example: C program for Bitwise AND

int main() { int a = 10, b = 8; printf(“Output = %d”, a&b); return 0; }

Output:

Explanation:

00001010 & 00001000 = 00001000 = 8 (In decimal)

#5 Assignment Operators

These types of operators help us assign a value to a variable.

Operator Function Example

= It will assign values from right-side operands to left-side operands a=b

+= It will add the right operand to the left operand and assign the result to left a+=b is the same as a=a+b

-= It will subtract the right operand from the left operand and assign the result to the left operand a-=b is the same as a=a-b

*= It will multiply the left operand with the right operand and assign the result to the left operand a*=b is the same as a=a*b

/= It will divide the left operand with the right operand and assign the result to the left operand a/=b is the same as a=a/b

%= It will calculate the modulus using two operands and assign the result to the left operand a%=b is the same as a=a%b

#6 Conditional Operators

Also, known as Ternary Operator or? : Operator, these operators are useful for decision-making.

Syntax:

Expression 1? Expression 2: Expression 3 #7 Special Operators

Here are some special operators used in C

Operator Function

& This operator is used to get the address of the variable.

Example: &a will give an address of a.

* This operator works as a pointer to a variable.

Example: * a where * is a pointer to the variable a.

size of () This operator gives the size of the variable.

Example: The size of (char) will give us 1.

Example: C program using a special operator

int main() { int *ptr, q; q = 40; /* It assigns the address of q to ptr */ ptr = &q; /* display q’s value using ptr variable */ printf(“%d”, *ptr); return 0; }

Output:

C Operators Precedence

Generally, arithmetic, logical, and relational operators are used while coding in C. The precedence for these operators in arithmetic is greater than logical and relational. Note that all the operators in arithmetic also follow a different order of precedence. Let’s check which operators hold the highest precedence.

Order of Precedence in Arithmetic Operators

The increment and decrement (+ + and – -) operators hold the highest precedence in arithmetic operators. After that next precedence is for the unary minus ( – ) operator; next, three operators, /, *, and %, have equal precedence. The lowest precedence is for the operators like addition ( + ) and subtraction ( – ). In case of equal priority, the compiler takes charge while evaluating them. Remember the C operator associativity rule for all operators with the same precedence. Then the execution happens from left to right.

For example,

int main() { int a = 15, b = 20, c = 32, result; result = a * b – ++c; printf(“The result is: %d”, result); return 0; }

Output:

Explanation: Here, in the given equation, first, “++” executes; hence the value of c will be 33. Next, “* “holds the highest precedence after “++.” Hence after the execution of “a * b,” the result will be 300. Then the execution of “-” happens and results in 267.

Order of Precedence in Relational/Logical Operators

For example,

Output: False

Misc Operators in C

The Misc operators or miscellaneous operators are conditional operators that include three operands. In these 3, the execution of the first operand happens first. Then the execution of the second operand, if it is non-zero, or a third operand executes to provide the necessary Output. Besides the operators discussed above, C programming language supports a few other special operators like sizeof and “?:”.

Operator Description Example

sizeof() Finds the size of a variable sizeof(b), if b is an integer, then the Output will be 4.

?: Conditional operator Condition? X: Y; here, if the condition is true, the result will be X, else Y.

& Address of a variable &a returns the actual address

* Pointer *a

Time and Space Complexity

Time and space complexity are the terms concerning the execution of an algorithm. The Time complexity is the time taken to run the algorithm as a function of the input. Space complexity is the space or memory the algorithm takes as an input function. These two terms depend on many terms like processor, operating system, etc.

Final Thoughts

C operators are the symbols used to perform relational, mathematical, bitwise, or logical operations. C language includes a lot of operators to perform various tasks as necessary in the program. Different kinds of operators are arithmetic, logical, and relational.

Frequently Asked Questions (FAQS)

Q1. What are the boolean operators in C?

Q2. What does ** mean in C?

Answer: The “**” in C is a double-pointer or pointer-to-pointer. Where * is a pointer that holds the address of the variable. ** mean the address of a variable already holding an address of a different variable.

Q3. What is the difference between prefix and postfix operators in C?

Answer: Prefix and postfix are the operators written before and after the operands. These operators are the increment (+ +) and decrement (- -) operators. For example, “++c” is the prefix operator, and “c++” is the postfix operator.

Q4. What is the Modulus operator?

Answer: The modulus operator is the arithmetic operator of C, and it works between two operands. The division of the numerator value by the denominator results in the remainder. In simpler words, the produced rest for the integer division is the modulus operator.

Q5. Does C language support operator overloading?

Answer: Operator overloading is a method of polymorphism where the programmer makes specific changes in the existing code without changing its meaning. Operator overloading is possible only in C++. Since polymorphism is possible only in an object-oriented language, C doesn’t support operator overloading.

Recommended Articles

This EDUCBA guide to C Operators discusses the operators used in C language with their syntax and examples. EDUCBA also suggests the following articles to learn more.

Working Of Transactions With Examples

Introduction to MongoDB Transactions

MongoDB transactions are provided in version 4.0 of Mongo DB where the transactions are supported even in Multi-document operations to maintain the ACID properties. The transactions are supported even across the sharded clusters and the replications of the documents in the Mongo database. There arise many situations where we need a transaction to maintain the atomicity in the operations where the process consists of multi-collection data or multi-document data which is supported by MongoDB transactions.

Start Your Free Data Science Course

In this article, we will have a look at the necessity of the transactions in MongoDB, the ACID properties of the transactions, and have a look at sample examples to demonstrate the use of Mongo DB transactions in your application.

MongoDB Transactions

There are multiple read and write operations being done from and to the Mongo DB database that needs a behavior where all those set of operations should be completed entirely or none of them should be reflected in the database. This integrity of a set of read and write operations is maintained by using transactions.

ACID properties of transactions

All the transactions in Mongo DB follow the properties of ACID which stand for Atomicity, Consistency, Isolation, and durability. It is important for exhibiting all these four characteristics inside your transaction for validation. Let us discuss one by one what all these four properties of ACID stand for –

Atomicity – By this property, we mean that all the operations that are present inside the transaction will together be treated as a single unit which means that the failure of even a single operation will lead to a rollback of all the previously executed operations of that transaction and marking the failure of the transaction. Inversely, if all the operations are executed successfully the transaction is also succeeded.

Consistency – By consistency in the database what we mean is that any changes in data will lead to the satisfaction of all the constraints applied on that column of a field in a database. For example, when a unique key is assigned to the document inside a collection then the field is always kept unique while maintaining its consistency.

Isolation is the property that helps in explaining the segregate execution of each transaction when multiple transactions are running in the system simultaneously.

Durability – Durability means the changes in the data being made in the database persist and are stored in the backing store as well which means is there is any kind of system failure arising then the data won’t be affected and will be stored and maintained properly.

Working of Transactions

We have to initiate a session in MongoDB with the help of the driver.

Further, you can make use of this session for executing all the operations that you wanted your transaction to carry out. This operation can be having the involvement of multiple documents, collections, and also across sharded clusters and all of them being ACID compliant.

Limitations of using transactions in MongoDB

There are many limitations while using the transactions in MongoDB which are as listed below –

Read operation cannot be performed on system collections.

Write operation cannot be done on non-existing collections or capped collections.

Indexes and collections cannot be modified or dropped in the transactions.

Example

Consider the following example of a transaction in Mongo DB.

The output of the execution of the above code snippet is as shown in the below image –

Further, we can decide if we want to commit the transaction or abort it by using the following statements –

sampleSession.abortTransaction()

Conclusion

The transactions can be single-document, multi-document, or even involving multiple clusters in it in the case of a distributed system. In Mongo DB the single document transactions are maintained internally. However, in the case of multi-document transactions, there is an extra overhead of managing these transactions. Transactions following the ACID properties make their database consistent, atomic, durable, and isolated. There are multiple methods using which we can initiate the session and abort or commit or transaction in Mongo DB.

Recommended Articles

This is a guide to MongoDB Transactions. Here we discuss the definition, Working of Transactions, examples with code implementation, limitations. You may also have a look at the following articles to learn more –

Attributes Of Matlab Pcolor() With Examples

Introduction to Matlab pcolor()

In MATLAB, pcolor() is the plotting function which is designed to represent the input matrix data in the form of an array of colored cells creating a pseudo color plot. The colored cell is termed as face. The plot gets created as x-y plane flat surface with x and y co-ordinates as vertices(corners) of faces. The limits for x and y co-ordinates are decided by the size of the input matrix.

Start Your Free Data Science Course

Hadoop, Data Science, Statistics & others

Syntax

There are different syntaxes that can be used to implement pcolor() method based on the input arguments given to it. Such as:

Where C is the input matrix data

pcolor(C)

Where C is the input matrix data

pcolor(X,Y,C)

X– x-coordinates of the vertices

ax defines the axes targeted for the plot

To store the pseudo color plot as surface object

Attributes of Matlab pcolor()

Here is the table of Attributes:

Attribute Description

C Input matrix data

X,Y coordinates of the vertices

Ax axes targeted for the plot

Examples to Implement Matlab pcolor()

Here are the examples mentioned:

Example #1

create pseudo color plot for input matric Cmat.

Code:

pcolor(Cmat);

Output:

Explanation: The input matrix is of size 2X3 and the vertices of the plot is decided 2X3 as default data. The pseudo color plot also can be created in the reverse direction using axis function.

Example #2

Generate Hadamard square orthogonal matrix and create pseudo color plot for same,with the origin set in the upper left corner.

Code:

axis square

Output:

Explanation: The resultant graph is a 40X40 two-color map, represented in the reverse direction.

Example #3

Create pseudo color plot for the input matrix data Cmat within the defined x and y coordinates given by matrix inputs X and Y.

Code:

pcolor(Xcod,Ycod,Cmat)

Output:

Explanation: The resultant plot has the vertices as per the values given by X and Y matrices and data from Cmat is plotted within the limits. The data from the input matrix are represented by different color code in the plot.

Example #4

MATLAB supports tilling of plots using the functions like nexttile() and tiledlayout(). The below code is wriiten to create 1X2 chart layout and creating two different pseudo color plot for two different set of inputs and functions in each cell of the layout.

pcolor(Rx,RCmat)

Output:

Explantion: The resultant plots are arranged in single layout consisting of two tiles generated using the function nexttile().

Pcolor() with Surface Object

When pcolor() method is assigned to a variable, it returns a surface object. This return value can be used to customize the properties of the plot after its creation.

Example #1

The below code is developed create a pseudo color plot for input matrix and modify the edge color and line width after the plot is generated.

Code:

s.LineWidth = 5;

Output:

Explanation: The resultant pseudo color plot is assigned to variable ‘s’. The edge color and the line width of the plot is modified using ‘s’ value as shown in the output plot.

Example #2

The below code snippet is designed to create the pseudo color plot and modify the face color of the cells using interpolated coloring using surface object properties.

Code:

s.FaceColor = ‘interp’;

Output:

Explanation: The resultant pseudo color plot is assigned to surface object ‘s’. The color representation of the faces are modified due to modification applied to the surface object property ‘facecolor’ for the surface object ‘s’.

Semi Logarithm Plotting using pcolor() Example #1

The below MATLAB code is designed to create semi logarithmic pseudo color plot and to alter the appearance using surface object properties from its return value.

Code:

s = pcolor(X,YL,Cmat);

Output:

Explanation: The resultant output is surface plot where y-coordinate input is the logarithmic function of x-coordinate inputs. The pseudo color semi logarithmic plot generated from the pcolor() method can be stored as surface object and its properties can be altered as shown in the below example:

Example #2

Code:

set(gca,’YTick’,logvals);

Output:

Explanation: The plot from the above code is generated with modified y-tick values by altering the properties of the surface object ‘s’.

Parametric Plotting using pcolor()

Parametric functions are also supported by pcolor() method.

Example #1

The below MATLAB code is designed to generate pseudo color plot from the x-y co oridinates generated from parametric equations.

Code:

pcolor(fX,fY,Cmat);

Explanation: The resultant plot represents the input matrix data, generated from repmat() function within the x-y coordinate values that are defined by two parametric equations.

Note: The size of the x-y coordinate grid must match the size of the input matrix data C. Based on the value in input matrix, the color map array gets colored from its vertices up to face chúng tôi first row gets mapped by the smallest value in C whereas the last row by the largest one, in the color map array. In case of long input array/matrix, the performance of pcolor() method seems to be slower.

Recommended Articles

This is a guide to Matlab pcolor(). Here we discuss an introduction to Matlab pcolor() with appropriate syntax and respective examples for better understanding. You can also go through our other related articles to learn more –

Update the detailed information about Types Of Xml Parsers With Examples on the Hatcungthantuong.com website. We hope the article's content will meet your needs, and we will regularly update the information to provide you with the fastest and most accurate information. Have a great day!