Do–while loop in Javascript - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a do–while loop in JavaScript?

A do–while loop runs a block of code once, then repeats it as long as a specified condition is true. It always runs the code at least once.

beginner

How does a do–while loop differ from a while loop?

A do–while loop runs the code block first, then checks the condition. A while loop checks the condition first before running the code.

beginner

What is the syntax of a do–while loop?

The syntax is:<br>

do {<br>  // code to run<br>} while (condition);

<br>The code runs once before the condition is checked.

intermediate

When is it useful to use a do–while loop?

Use a do–while loop when you want the code to run at least once, like asking a user for input and then repeating if the input is invalid.

beginner

What happens if the condition in a do–while loop is false the first time it is checked?

The code inside the loop still runs once before the condition is checked. If the condition is false, the loop stops after that first run.

What is guaranteed about the code inside a do–while loop?

A It runs at least once

B It may not run at all

C It runs only if the condition is true initially

D It runs twice before checking the condition

A do–while loop always runs the code block once before checking the condition.

Which part of the do–while loop is checked after the code runs?

A The code block

B The condition in the <code>while</code> statement

C The initialization

D The loop counter

After running the code block, the loop checks the condition in the while statement to decide if it should run again.

What will happen if the condition in a do–while loop is always true?

A The loop will run twice

B The loop will run once

C The loop will not run

D The loop will run forever (infinite loop)

If the condition never becomes false, the do–while loop will continue running endlessly.

Which of these is the correct syntax for a do–while loop?

A while { /* code */ } do (condition);

B while (condition) { /* code */ } do;

C do { /* code */ } while (condition);

D do while (condition) { /* code */ };

The correct syntax is do { /* code */ } while (condition); with a semicolon at the end.

Why might you choose a do–while loop over a while loop?

A To ensure the code runs at least once

B To skip the first iteration

C To run the loop only if the condition is false

D To avoid checking the condition

A do–while loop guarantees the code runs at least once, unlike a while loop.

Explain how a do–while loop works and when you would use it.

Think about the difference from a <code>while</code> loop and real-life situations where you want to try something first.

Write the syntax of a do–while loop and describe each part.

Remember the order: do, code, while(condition);