strrchr

(PHP 4, PHP 5, PHP 7, PHP 8)

strrchr — Find the last occurrence of a character in a string

Опис

strrchr(string $haystack, string $needle, bool $before_needle = false): string|false

This function returns the portion of haystack which starts at the last occurrence of needle and goes until the end of haystack.

Параметри

haystack

The string to search in

needle

If needle contains more than one character, only the first is used. This behavior is different from that of strstr().

До версії PHP 8.0.0, якщо параметр needle не є рядком, він перетворюється на ціле число і розглядається як код символу. Ця поведінка є застарілою, починаючи з PHP 7.3.0. Вкрай не рекомендується на неї покладатися. Залежно від потрібної поведінки, параметр needle необхідно привести до рядкового типу або обробити функцією chr().

before_needle

If true, strrchr() returns the part of the haystack before the last occurrence of the needle (excluding the needle).

Значення, що повертаються

This function returns the portion of string, or false if needle is not found.

Журнал змін

Версія	Опис
8.3.0	The `before_needle` parameter was added.
8.0.0	Тепер параметр `needle` може бути порожнім рядком.
8.0.0	Passing an int as `needle` is no longer supported.
7.3.0	Passing an int as `needle` has been deprecated.

Приклади

Приклад #1 strrchr() example

<?php
$ext = strrchr('somefile.txt', '.');
echo "file extension: $ext \n";
$ext = $ext ? strtolower(substr($ext, 1)) : '';
echo "file extension: $ext";
?>

Поданий вище приклад виведе щось схоже на:

file extension: .txt
file extension: txt

Примітки

Зауваження: Ця функція є бінарно безпечною.

Прогляньте також

strstr() - Find the first occurrence of a string
strrpos() - Find the position of the last occurrence of a substring in a string

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User Contributed Notes 8 notes

down

matthewkastor at live dot com ¶

13 years ago

<?php

/**

 * Removes the preceeding or proceeding portion of a string

 * relative to the last occurrence of the specified character.

 * The character selected may be retained or discarded.

 * 

 * Example usage:

 * <code>

 * $example = 'http://example.com/path/file.php';

 * $cwd_relative[] = cut_string_using_last('/', $example, 'left', true);

 * $cwd_relative[] = cut_string_using_last('/', $example, 'left', false);

 * $cwd_relative[] = cut_string_using_last('/', $example, 'right', true);

 * $cwd_relative[] = cut_string_using_last('/', $example, 'right', false);

 * foreach($cwd_relative as $string) {

 *     echo "$string <br>".PHP_EOL;

 * }

 * </code>

 * 

 * Outputs:

 * <code>

 * http://example.com/path/

 * http://example.com/path

 * /file.php

 * file.php

 * </code>

 * 

 * @param string $character the character to search for.

 * @param string $string the string to search through.

 * @param string $side determines whether text to the left or the right of the character is returned.

 * Options are: left, or right.

 * @param bool $keep_character determines whether or not to keep the character.

 * Options are: true, or false.

 * @return string

 */

function cut_string_using_last($character, $string, $side, $keep_character=true) {

    $offset = ($keep_character ? 1 : 0);

    $whole_length = strlen($string);

    $right_length = (strlen(strrchr($string, $character)) - 1);

    $left_length = ($whole_length - $right_length - 1);

    switch($side) {

        case 'left':

            $piece = substr($string, 0, ($left_length + $offset));

            break;

        case 'right':

            $start = (0 - ($right_length + $offset));

            $piece = substr($string, $start);

            break;

        default:

            $piece = false;

            break;

    }

    return($piece);

}

?>

down

sekati at gmail dot com ¶

18 years ago

just a small addition to carlos dot lage at gmail dot com note which makes it a bit more useful and flexible:

<?php
// return everything up to last instance of needle
// use $trail to include needle chars including and past last needle 
function reverse_strrchr($haystack, $needle, $trail) {
    return strrpos($haystack, $needle) ? substr($haystack, 0, strrpos($haystack, $needle) + $trail) : false;
}
// usage:
$ns = (reverse_strrchr($_SERVER["SCRIPT_URI"], "/", 0));
$ns2 = (reverse_strrchr($_SERVER["SCRIPT_URI"], "/", 1));
echo($ns . "<br>" . $ns2);
?>

down

dchris1 at bigpond dot net dot au ¶

20 years ago

The function provided by marcokonopacki at hotmail dot com isn't really a reverse-version of strrchr(), rather a reverse version of strchr(). It returns everything from the start of $haystack up to the FIRST instance of the $needle. This is basically a reverse of the behavior which you expect from strchr(). A reverse version of strrchr() would return everything in $haystack up to the LAST instance of $needle, eg:

<?php
// reverse strrchr() - PHP v4.0b3 and above
function reverse_strrchr($haystack, $needle)
{
    $pos = strrpos($haystack, $needle);
    if($pos === false) {
        return $haystack;
    }
    return substr($haystack, 0, $pos + 1);
}
?>

Note that this function will need to be modified slightly to work with pre 4.0b3 versions of PHP due to the return type of strrpos() ('0' is not necessarily 'false'). Check the documentation on strrpos() for more info. 

A function like this can be useful for extracting the path to a script, for example:

<?
$string = "/path/to/the/file/filename.php";

echo reverse_strrchr($string, '/'); // will echo "/path/to/the/file/"
?>

down

readless at gmx dot net ¶

18 years ago

to: repley at freemail dot it

the code works very well, but as i was trying to cut script names (e.g.: $_SERVER["SCRIPT_NAME"] => /index.php, cut the string at "/" and return "index.php") it returned nothing (false). i've modified your code and now it works also if the needle is the first char.
- regards from germany

<?php
//strxchr(string haystack, string needle [, bool int leftinclusive [, bool int rightinclusive ]])
function strxchr($haystack, $needle, $l_inclusive = 0, $r_inclusive = 0){
   if(strrpos($haystack, $needle)){
       //Everything before last $needle in $haystack.
       $left =  substr($haystack, 0, strrpos($haystack, $needle) + $l_inclusive);
 
       //Switch value of $r_inclusive from 0 to 1 and viceversa.
       $r_inclusive = ($r_inclusive == 0) ? 1 : 0;
 
       //Everything after last $needle in $haystack.
       $right =  substr(strrchr($haystack, $needle), $r_inclusive);
 
       //Return $left and $right into an array.
       return array($left, $right);
   } else {
       if(strrchr($haystack, $needle)) return array('', substr(strrchr($haystack, $needle), $r_inclusive));
       else return false;
   }
}
?>

down

freakinunreal at hotmail dot com ¶

18 years ago

to marcokonopacki at hotmail dot com.

I had to make a slight change in your function for it to return the complete needle inclusive.

// Reverse search of strrchr.
function strrrchr($haystack,$needle)
{

   // Returns everything before $needle (inclusive).
   //return substr($haystack,0,strpos($haystack,$needle)+1);
   // becomes
   return substr($haystack,0,strpos($haystack,$needle)+strlen($needle));
}

Note: the +1 becomes +strlen($needle)

Otherwise it only returns the first character in needle backwards.

down

Primo Anderson Do S?tio ¶

19 years ago

$filename = 'strrchr_test.php';
print strrchr( $filename, '.' );

Result:
.php

$other_filename = 'strrchr_test.asp.php';
print  strrchr( $other_filename, '.' );

Result:
.php

down

marcokonopacki at hotmail dot com ¶

21 years ago

<?

// Reverse search of strrchr.
function strrrchr($haystack,$needle)
{

    // Returns everything before $needle (inclusive).
    return substr($haystack,0,strpos($haystack,$needle)+1);
    
}

$string = "FIELD NUMBER(9) NOT NULL";

echo strrrchr($string,")"); // Will print FIELD (9)

?>

down

-5

carlos dot lage at gmail dot com ¶

19 years ago

I used dchris1 at bigpond dot net dot au 's reverse strrchr and reduced it to one line of code and fixed it's functionality - the real strrchr() returns FALSE if the needle is not found, not the haystack :)

<?php
// reverse strrchr()
function reverse_strrchr($haystack, $needle)
{
                return strrpos($haystack, $needle) ? substr($haystack, 0, strrpos($haystack, $needle) +1 ) : false;
} 
?>

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