How Do PHP's `startsWith()` and `endsWith()` Functions Work, and What Are Their Built-in Equivalents?

Investigating the startsWith() and endsWith() Functions in PHP

To check whether a given string begins or concludes with a particular character or substring, you can implement two functions: startsWith() and endsWith().

Defining the Functions

startsWith()

function startsWith($haystack, $needle) {
    $length = strlen($needle);
    return substr($haystack, 0, $length) === $needle;
}

This function checks if the initial portion of the haystack matches the specified needle. If they do, it returns true; otherwise, it returns false.

endsWith()

function endsWith($haystack, $needle) {
    $length = strlen($needle);
    if (!$length) {
        return true;
    }
    return substr($haystack, -$length) === $needle;
}

The endsWith() function works similarly, but it examines the end of the haystack for the presence of the needle.

Example Usage

Consider the following code snippet:

$str = '|apples}';

echo startsWith($str, '|'); // Returns true
echo endsWith($str, '}'); // Returns true

In this example, the startsWith() function checks if the string begins with the pipe character '|', and it returns true because the string indeed starts with that character. Similarly, the endsWith() function verifies that the string ends with the '}' curly brace, also returning true.

PHP 8.0 and Above

In PHP 8.0 and later versions, the str_starts_with() and str_ends_with() functions provide a built-in solution for these tasks. They offer improved performance and ease of use compared to custom implementations.

The above is the detailed content of How Do PHP's `startsWith()` and `endsWith()` Functions Work, and What Are Their Built-in Equivalents?. For more information, please follow other related articles on the PHP Chinese website!