While loop execution flow in Java - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the basic structure of a while loop in Java?

A while loop starts with the keyword while, followed by a condition in parentheses. The loop body is enclosed in braces and runs repeatedly as long as the condition is true.

beginner

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

The loop body does not execute even once. The program skips the loop and continues with the next statements after the loop.

beginner

How does the while loop decide whether to run the loop body again?

After each execution of the loop body, the condition is checked again. If it is true, the loop runs again; if false, the loop stops.

intermediate

What can cause an infinite while loop?

If the condition never becomes false, the loop keeps running forever. This usually happens if the loop variable is not updated inside the loop.

beginner

Explain the flow of a while loop with an example: <br>

int i = 0; while (i < 3) { System.out.println(i); i++; }

1. Start with i = 0.<br>2. Check if i < 3 (true).<br>3. Print i (0).<br>4. Increase i by 1 (i = 1).<br>5. Repeat steps 2-4 until i is 3.<br>6. When i = 3, condition is false, loop stops.

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

A The loop body does not run at all

B The loop body runs once

C The loop runs infinitely

D The program crashes

If the condition is false initially, the while loop skips the body and continues after the loop.

When is the condition in a while loop checked?

A Only once after the loop ends

B Before each loop iteration

C Only once before the loop starts

D After each loop iteration

The while loop checks the condition before running the loop body each time.

What can cause an infinite while loop?

A Condition never becomes false

B Condition is false at start

C Loop body is empty

D Using break statement inside loop

If the condition never changes to false, the loop runs forever.

Which keyword is used to start a while loop in Java?

A repeat

B for

C loop

D while

The keyword while starts a while loop.

What happens after the loop body executes in a while loop?

A The loop ends immediately

B The program restarts

C The condition is checked again

D The loop body runs twice

After each loop body execution, the condition is checked to decide if the loop runs again.

Describe the step-by-step execution flow of a while loop in Java.

Think about what happens before and after the loop body runs.

Explain why a while loop might run forever and how to prevent it.

Consider what controls the loop's stop condition.