Javascript Introduction
Comments in Javascript
Javascript Variables
Difference between var, let and const in Javascript
Datatypes
Assignment Operators
Logical Operators
Comparison Operators
Actions alert, prompt & confirm

Javascript Flow Control
Conditional Statements in Javascript
Nullish coalescing operator in Javascript
Break and Continue in Javascript
Loops in javascript
for loop in Javascript
while loop

Javascript Functions
Javascript Functions
JavaScript Arrow Function

Javascript Objects
Javascript Objects

Javascript Array
Javascript Arrays

Javascript Error Handling
Error Handling in Javascript

Javascript ES6
Set
Javascript Spread Operator
Rest Parameter in Javascript

Javascript Asynchronous
Javascript Callback Function
Promises in Javascript
Promise Chaining
Async-Await in Javascript

Javascript DOM
DOM Document
DOM Elements
DOM Attributes
DOM Manipulation
DOM Node Lists
Javascript Events
DOM Traversing Elements
DOM EventListener

Javascript Class
Classes in javascript
Class Inheritance

Javascript Design Principles
SOLID - The Single responsibility principle in javascript
SOLID - Open-Closed principle in Javascript

Other Topics
Javascript Hoisting
Filter, Map and Reduce functions in Javascript
Closure in Javascript
Optional chaining operator in Javascript
Consoling in table format in javascript
Fetch API in Javascript
HTML web Storage API
Checking the online or offline status of the browser

for loop in javascript

Published on: July 03, 2021 By T.Andrew Rayan

for loop:

The 'for' loop in javascript is used to execute a block of codes repeatedly again and again until a particular condition is satisfied.

Syntax for the for loop:

for(initialization; condition; increment/decrement){
 // block of codes.
}

The intialization statement is executed only once during the first execution in the for loop.

The condition is checked to execute the block of codes. If condition is not satisfied then it will stop executing the loop. The increment or decrement statement is used to increment or decrement any value, usually the variable initialized in the initialization statement.

Example for the for loop:

        
for(let i=1;i<=10;i++){
   console.log(`i = ${i}`);
}

This will print the value from 1 to 10 to the console. The first block in 'for' loop is initialization. This happens only once. Next we check the condition whether the value of 'i' is less than or equal to 10 if it satisfies then it prints the value of 'i' to the console.

Next time when executing the loop the value of 'i' is incremented because of the 3rd statement 'i++'. This continues until the condition gets false.

For loop can also be used to loop through the objects properties and the arrays using 'for/of' and 'for/in' loops.

for/in loop:

The 'for/in' loop is used to loop through the properties of the object.

Syntax for for/in loop:

for(let value in object){
  // block of codes.
}

Example for for/in loop:

        
var employee = {name:'Andrew',age:30};

for(let prop in employee){
   console.log(`${prop} is employee[prop]`);
}

Result

name is Andrew
age is 30

In the above example using for/in loop we loop through the employee object and display its property name and its value.

for/of loop:

The 'for/of' loop is used to loop through the array or any collections.

Syntax for the for/of loop:

for(let value in object){
  // block of codes.
}

Example for the for/of loop:

        
let employees = [
    {name:'Andrew',age:30},
    {name:'John',age:28}];
for(let employee of employees){
    console.log(employee.name);
}


    

Output

Andrew
John

This will loop through the employees array and displays the name of the employee.

for loop in javascript

Published on: July 03, 2021 By T.Andrew Rayan

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