Loop (Iteration) Statements in JavaScript

Loop(Iteration) Statement

A loop describes the process in a software program/script that repeats the same set of instructions over and over until it receives the order to stop.

Loops offer a quick and easy way to execute something repeatedly. There are 4 types of loop in JavaScript:

  • for statment
  • for/in statement
  • while statment
  • do/while statement

for Statement

The for is a loop statement that is executed as long as the given condition is true. It will not stop until and unless the condition becomes false.

Example of for statement

For/in Statement

  • This statement loops through the properties of an object.
  • The block of code snippet inside the loop will be executed once for each of the properties.

While Statement

  • while is a loop statement that is executed as long as the given condition is true. It will not stop until and unless the condition becomes false.
  • Initialization of loop variable is mandatory before writing while loop.

Example of while statment

do-while Loop

  • It loops through a block of code once at first and then repeats the loop while the specified condition is true.
  • The main difference between do-while and while loop is that in do-while loop, the set of statements are executed at least once even if the condition isn’t satisfied whereas in while loop nothing is executed if the condition is false.

Example: of do while statement