Do-while loop execution model in PHP - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a do-while loop in PHP?

A do-while loop is a control structure that executes a block of code once, and then repeats the loop as long as a specified condition is true.

beginner

How does the execution order of a do-while loop differ from a while loop?

A do-while loop executes the code block first, then checks the condition. A while loop checks the condition first before executing the code block.

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What will happen if the condition in a do-while loop is false on the first check?

The code block will still run once before the condition is checked and the loop stops.

beginner

Write the basic syntax of a do-while loop in PHP.

do { // code to execute } while (condition);

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

You use a do-while loop when you want the code inside the loop to run at least once, regardless of the condition.

In a do-while loop, when is the condition checked?

A After executing the loop body once

B Before executing the loop body

C At the same time as executing the loop body

D Only if the loop body has executed more than once

The do-while loop always executes the loop body first, then checks the condition.

What will this PHP code output? $i = 5; do { echo $i . ' '; $i++; } while ($i < 5);

A No output

B 5 6

C 5

D Infinite loop

The loop runs once printing 5, then checks condition ($i < 5) which is false, so it stops.

Which of these is true about do-while loops?

A They are identical to while loops

B They never run if the condition is false initially

C They check the condition before running the loop body

D They always run the loop body at least once

Do-while loops execute the loop body first, so they always run at least once.

What keyword starts a do-while loop in PHP?

A while

B do

C loop

D repeat

The do-while loop starts with the keyword 'do'.

If you want to ensure a block of code runs at least once, which loop should you use?

A do-while loop

B while loop

C for loop

D foreach loop

The do-while loop guarantees the code runs once before checking the condition.

Explain how the do-while loop executes in PHP and why it might be useful.

Think about when you want code to run before checking a condition.

Write a simple PHP do-while loop that prints numbers from 1 to 3.

Start with a variable at 1 and increase it inside the loop.