Php - startsWith() and endsWith() functions in PHP

phpstring

How can I write two functions that would take a string and return if it starts with the specified character/string or ends with it?

For example:

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

Best Solution

PHP 8.0 and higher

Since PHP 8.0 you can use the

str_starts_with Manual and

str_ends_with Manual

Example

echo str_starts_with($str, '|');

PHP before 8.0

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

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

This is the style that Microsoft tends to use in their examples.

It appears that the guidance in this area may have changed, as StyleCop now enforces the use of the C# specific aliases.

Javascript - endsWith in JavaScript

UPDATE (Nov 24th, 2015):

This answer is originally posted in the year 2010 (SIX years back.) so please take note of these insightful comments:

Shauna -

Update for Googlers - Looks like ECMA6 adds this function. The MDN article also shows a polyfill. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/endsWith

T.J. Crowder -

Creating substrings isn't expensive on modern browsers; it may well have been in 2010 when this answer was posted. These days, the simple this.substr(-suffix.length) === suffix approach is fastest on Chrome, the same on IE11 as indexOf, and only 4% slower (fergetaboutit territory) on Firefox: jsperf.com/endswith-stackoverflow/14 And faster across the board when the result is false: jsperf.com/endswith-stackoverflow-when-false Of course, with ES6 adding endsWith, the point is moot. :-)

ORIGINAL ANSWER:

I know this is a year old question... but I need this too and I need it to work cross-browser so... combining everyone's answer and comments and simplifying it a bit:

String.prototype.endsWith = function(suffix) {
    return this.indexOf(suffix, this.length - suffix.length) !== -1;
};

Doesn't create a substring
Uses native indexOf function for fastest results
Skip unnecessary comparisons using the second parameter of indexOf to skip ahead
Works in Internet Explorer
NO Regex complications

Also, if you don't like stuffing things in native data structure's prototypes, here's a standalone version:

function endsWith(str, suffix) {
    return str.indexOf(suffix, str.length - suffix.length) !== -1;
}

EDIT: As noted by @hamish in the comments, if you want to err on the safe side and check if an implementation has already been provided, you can just adds a typeof check like so:

if (typeof String.prototype.endsWith !== 'function') {
    String.prototype.endsWith = function(suffix) {
        return this.indexOf(suffix, this.length - suffix.length) !== -1;
    };
}

Best Solution

PHP 8.0 and higher

Example

PHP before 8.0

Related Solutions

C# - the difference between String and string in C#

This is the style that Microsoft tends to use in their examples.

Javascript - endsWith in JavaScript

Related Question