How Can I Exit a Loop Prematurely in PHP?

Exiting Loops in PHP

In PHP, you may encounter situations where you need to terminate a loop prematurely, especially when performing error checking or conditional processing. This article explores how to exit a loop in PHP using the break statement.

Looping with Error Checking

The provided code snippet demonstrates a loop that involves error checking. However, it continues looping even after an error is encountered, which is inefficient.

Breaking the Loop with break

To exit a loop in PHP, you can use the break statement. When executed within a loop, break immediately terminates the loop and execution proceeds to the code following it.

Here's an example:

foreach($results as $result) {
    if (!$condition) {
        ErrorHandler::addErrorToStack('Unexpected result.');
        break;
    }

    doSomething();
}

// No need to check for $halt here since it's no longer necessary

In this code, if the condition evaluates to false, the break statement is executed, terminating the loop and moving execution to the code after the loop.

Note:

• The break statement can also be used to escape from nested loops.
• The optional numeric parameter for break allows you to escape from multiple levels of nested loops.

Example of Breaking from a Nested Loop:

while ($outer) {
    while ($inner) {
        if ($condition) {
            break 2;
        }
    }
    doSomethingElse();
}

This code escapes from both the $outer and $inner loops when the condition is met.

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