For loop execution model in PHP - Cheat Sheet & Quick Revision

Recall & Review

beginner

What are the three main parts of a for loop in PHP?

The three main parts are:<br>1. Initialization (runs once at the start)<br>2. Condition (checked before each loop iteration)<br>3. Increment/Decrement (runs after each iteration)

beginner

Explain the order of execution in a PHP for loop.

First, the initialization runs once.<br>Then, the condition is checked.<br>If true, the loop body runs.<br>After the body, the increment/decrement runs.<br>This repeats until the condition is false.

beginner

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

The loop body does not run at all.<br>The program skips the loop and continues after it.

intermediate

Can the increment part of a for loop be empty in PHP? What does that mean?

Yes, it can be empty.<br>This means no automatic change happens after each iteration.<br>You must manually change the loop variable inside the loop body to avoid infinite loops.

beginner

Show a simple PHP for loop that prints numbers 1 to 5.

Example:<br>

<?php
for ($i = 1; $i <= 5; $i++) {
    echo $i . "\n";
}
?>

<br>This prints numbers 1, 2, 3, 4, 5 each on a new line.

In a PHP for loop, which part runs only once at the start?

A Condition

B Initialization

C Increment

D Loop body

Initialization runs once before the loop starts to set up the loop variable.

What happens if the condition in a PHP for loop is false initially?

A The loop body does not run

B The loop runs infinitely

C The increment runs once

D The loop runs once

If the condition is false at the start, the loop body does not execute at all.

Which part of the for loop runs after each iteration?

A Increment

B Condition

C Initialization

D Loop body

The increment part runs after each loop iteration to update the loop variable.

Is it possible to have an empty increment section in a PHP for loop?

A Yes, and the loop will run infinitely

B No, it is required

C Yes, but you must update the variable inside the loop

D No, it causes a syntax error

You can leave increment empty but must update the loop variable inside the loop to avoid infinite loops.

What is the correct syntax for a PHP for loop that counts from 0 to 4?

A for ($i = 5; $i > 0; $i--)

B for ($i = 1; $i <= 5; $i++)

C for ($i = 0; $i <= 5; $i--)

D for ($i = 0; $i < 5; $i++)

Option D correctly counts from 0 up to 4 by incrementing $i until it is less than 5.

Describe the execution flow of a PHP for loop from start to finish.

Think about what happens before, during, and after each loop cycle.

Explain what happens if you forget to update the loop variable inside a for loop with an empty increment section.

Consider what keeps the loop going or stopping.