Script execution and memory reset in PHP - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this PHP script?

Consider the following PHP code that uses a static variable inside a function. What will be printed after running the script?

PHP

<?php
function counter() {
    static $count = 0;
    $count++;
    echo $count . ' ';
}
counter();
counter();
counter();
?>

A 1 1 1

B 0 1 2

C 1 2 3

D 3 3 3

💡 Hint

Static variables keep their value between function calls.

The static variable $count is initialized only once. Each call increments it, so the output is 1 2 3 .

❓ Predict Output

intermediate

What happens to variables after script execution ends?

In PHP, what happens to all variables after the script finishes running?

A All variables are cleared from memory and reset for the next script run.

B Variables keep their values and are available in the next script execution automatically.

C Variables are saved to a file automatically for persistence.

D Variables are converted to global constants after script ends.

💡 Hint

Think about how PHP runs scripts for each request.

PHP runs scripts fresh each time. After execution, all variables are cleared from memory and reset.

🔧 Debug

advanced

Why does this PHP script output '1 1 1' instead of '1 2 3'?

Look at this PHP code snippet. It is intended to print 1 2 3 but prints 1 1 1 instead. Why?

PHP

<?php
function counter() {
    $count = 0;
    $count++;
    echo $count . ' ';
}
counter();
counter();
counter();
?>

A Because $count is a local variable reset to 0 on every call.

B Because $count is declared static but not incremented properly.

C Because echo is buffering output incorrectly.

D Because the function is called only once.

💡 Hint

Check how the variable $count is declared inside the function.

The variable $count is a normal local variable, so it resets to 0 every time the function runs. It never remembers previous values.

❓ Predict Output

advanced

What is the output of this PHP script using session variables?

This PHP script uses a session variable to count visits. What will it output on the third page load?

PHP

<?php
session_start();
if (!isset($_SESSION['visits'])) {
    $_SESSION['visits'] = 0;
}
$_SESSION['visits']++;
echo $_SESSION['visits'];
?>

A Error: Undefined index 'visits'

B 1

C 0

D 3

💡 Hint

Session variables keep data between page loads for the same user.

The session variable visits increments each time the page loads. On the third load, it will be 3.

🧠 Conceptual

expert

How does PHP handle memory between separate script executions?

Which statement best describes how PHP manages memory and variables between separate script executions in a typical web server environment?

A PHP keeps all variables in memory between executions to speed up processing automatically.

B Each script execution starts with a fresh memory state; variables do not persist unless explicitly stored externally.

C Variables are saved in a shared memory pool accessible by all scripts without session or database use.

D PHP scripts share global variables across all users and requests by default.

💡 Hint

Think about how PHP runs scripts on a web server for each request.

PHP runs each script independently with a clean memory state. Variables only persist if saved in sessions, files, or databases.