JavaScript Operator

There are many types of operator some are:

Arithmetic Operator

Arithmetic operators are used to perform arithmetic operations on the operands.

Assignment Operator

The following operators are known as JavaScript assignment operators.

Logical Operator

The following operators are known as JavaScript logical operators.

Relation or Comparision Operator

The JavaScript comparison operator compares the two operands.

Conditional Statement

The JavaScript if-else statement is used to execute the code whether condition is true or false. There are three forms of if statement in JavaScript.
i. If Statement
ii. If else statement
iii. if else if statement

If Statement

It evaluates the content only if expression is true. The signature of JavaScript if statement is given below.

If else Statement

It evaluates the content whether condition is true of false. The syntax of JavaScript if-else statement is given below.

If else if Statement

It evaluates the content only if expression is true from several expressions. The signature of JavaScript if else if statement is given below.

JavaScript Switch

The switch statement is a conditional statement like if statement. Switch is useful when you wnat to like execute one of the multiple code blocks based on the return value of a specified expression.

JavaScript Loops

The JavaScript loops are used to iterate the piece of code using for, while, do while or for-in loops. It makes the code compact. It is mostly used in array.
There are four types of loops in JavaScript.
i. for loop
ii. while loop
iii. do-while loop

for loop

The JavaScript for loop iterates the elements for the fixed number of times. It should be used if number of iterations is known. The syntax of for loop is given below.

while loop

The JavaScript while loop iterates the elements for the infinite number of times. It should be used if number of iteration is not known. The syntax of while loop is given below.

do-while loop

The JavaScript do while loop iterates the elements for the infinite number of times like while loop. but, code is executed at least once whether condition is true or false. The syntax of do while loop is given below

JavaScript Array

JavaScript array is an object that represents a collection of similar type of elements. There are 3 ways to construct array in JavaScript
i. By array literal by
ii. By creating instance of Array directly (using new keyword)
iii. By using an Array constructor (using new keyword)

By array literal by

The syntax of creating array using array literal is given below:

var arrayname=[value1,value2.....valueN];

By creating instance of Array directly (using new keyword)

The syntax of creating array directly is given below:

var arrayname=new Array();

By using an Array constructor (using new keyword)

Here, you need to create instance of array by passing arguments in constructor so that we don't have to provide value explicitly. The example of creating object by array constructor is given below.

JavaScript Object

A JavaScript object is an entity having state and behavior (properties and method). For example: car, pen, bike, chair, glass, keyboard, monitor etc. JavaScript is an object-based language. Everything is an object in JavaScript. JavaScript is template based not class based. Here, we don't create class to get the object. But, we direct create objects.
There are 3 ways to create objects:
i. By object literal
ii. By creating instance of Object directly (using new keyword)
iii. By using an object constructor (using new keyword)

By object literal

The syntax of creating object using object literal is given below:

object={property1:value1,property2:value2.....propertyN:valueN}

By creating instance of Object directly (using new keyword)

The syntax of creating object directly is given below:

var objectname=new Object();

By using an object constructor (using new keyword)

Here, you need to create function with arguments. Each argument value can be assigned in the current object by using this keyword. This keyword refers to the current object. The example of creating object by object constructor is given below.

JavaScript Function

A function is a block of code that performs a specific task. It takes in input, Processes it, and produces output. Function always returns the value.

Declaring a function

• A function is declared using the function keyword.
• The basic rules of naming a function are similar to naming a variable. It is better to write a descriptive name for your function. For example, if a function is used to add two numbers, you could name the function add or addNumbers.
• The body of function is written within {}.

Calling a Function