PHP – Implement startsWith() and endsWith() functions

This post shows you how to implement startsWith and endsWith functions in PHP.

1. startsWith() function

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

The function startsWith function that checks whether the string starts with a specified prefix, i.e. it returns true if the $needle string is a prefix of the $haystack string, false if it does not.

Code example:

$message = 'Foo and Bar';
if (startsWith($message, 'Foo')) {
    echo 'The message starts with Foo';
} else {
    echo 'The message does not start with Foo';
}

Output:

The message starts with Foo

2. endsWith() function

function endsWith($haystack, $needle)
{
    $length = strlen($needle);
    return ($needle === '') 
            || (substr($haystack, -$length) === $needle);
}

The endsWith function that checks whether the string ends with a specified suffix, i.e. it returns true if the $needle string is a suffix of the $haystack string, false if it does not.

Code example:

$message = 'Foo and Bar';
if (endsWith($message, 'Bar')) {
    echo 'The message ends with Bar';
} else {
    echo 'The message does not end with Bar';
}

Output:

The message ends with Bar