While loop in Javascript - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a while loop in JavaScript?

A while loop repeats a block of code as long as a specified condition is true. It checks the condition before each repetition.

beginner

How does the condition in a while loop affect its execution?

The loop runs only if the condition is true. If the condition is false at the start, the loop body does not run at all.

intermediate

What happens if the condition in a while loop never becomes false?

The loop will run forever, causing an infinite loop. This can freeze or crash the program.

beginner

Write the basic syntax of a while loop in JavaScript.

while (condition) { // code to run repeatedly }

beginner

Why is it important to update variables inside a while loop?

Updating variables inside the loop helps change the condition so the loop can eventually stop. Without this, the loop might run forever.

What does a while loop do in JavaScript?

A Runs code once then stops

B Runs code only if condition is false

C Repeats code while a condition is true

D Repeats code a fixed number of times

A while loop repeats the code block as long as the condition remains true.

When is the condition in a while loop checked?

A Before each loop iteration

B After each loop iteration

C Only once before the loop starts

D Only after the loop ends

The condition is checked before running the loop body each time.

What happens if the while loop condition is false at the start?

A The loop runs twice

B The loop body does not run at all

C The loop runs once

D The loop runs infinitely

If the condition is false initially, the loop body is skipped completely.

Which of these can cause an infinite while loop?

A Not updating the condition inside the loop

B Updating the condition to false

C Using a for loop instead

D Using a break statement

If the condition never changes to false, the loop never stops.

What is the correct syntax to start a while loop?

A while condition ( ) { }

B while { condition }

C while: condition { }

D while (condition) { }

The correct syntax uses parentheses around the condition and curly braces for the loop body.

Explain how a while loop works and why updating the condition inside the loop is important.

Think about what happens if the condition never changes.

Describe a real-life situation where a while loop could be useful.

Imagine waiting for something to happen before moving on.