While Loops

A while loop in JavaScript allows you to execute a block of code repeatedly as long as a specified condition is true.

How to write a while loop in JavaScript

while (condition) {
  // code block to be executed
}

Example

let i = 0;

while (i < 10) {
  console.log(`The number is ${i}`);
  i++;
}
console.log("The program is finished");

• A variable i has been set to 0.

• The while loop's condition is i < 10

  • As long as the loop's condition is evaluated to true it will repeat its code block

• The code block will do the following:

  • Output The number is {i} depending on the value of i

  • Increase i by one.

• The while loop will recheck its condition to see if it is true or false

  • if true, it will execute its code block

  • if false, it will move on with the rest of the code

Key Points

• Condition Check: The condition is evaluated before each iteration. If the condition is false initially, the loop body will not execute at all.

• Use Cases: while loops are useful when the number of iterations is not known beforehand and depends on some dynamic condition.