Split a string on the last occurring space

Question

I need to split a string into two parts. The string contains words separated by a space and can contain any number of words, e.g:

$string = "one two three four five";

The first part needs to contain all of the words except for the last word.

The second part needs to contain just the last word.

EDIT: The two parts need to be returned as strings, not arrays, e.g:

$part1 = "one two three four";

$part2 = "five";

Solution 1

Couple ways you can go about it.

Array operations:

$string ="one two three four five";
$words = explode(' ', $string);
$last_word = array_pop($words);
$first_chunk = implode(' ', $words);

String operations:

$string="one two three four five";
$last_space = strrpos($string, ' ');
$last_word = substr($string, $last_space);
$first_chunk = substr($string, 0, $last_space);

Solution 2

What you need is to split the input string on the last space. Now a last space is a space which is not followed by any more spaces. So you can use negative lookahead assertion to find the last space:

$string="one two three four five";
$pieces = preg_split('/ (?!.* )/',$string);

Solution 3

Have a look at the explode function in PHP

Returns an array of strings, each of which is a substring of string formed by splitting it on boundaries formed by the string delimiter

Solution 4

Use strrpos to get last space character's position, then substr to divide the string with that position.

<?php
    $string = 'one two three four five';
    $pos = strrpos($string, ' ');
    $first = substr($string, 0, $pos);
    $second = substr($string, $pos + 1);
    var_dump($first, $second);
?>

Live example

Solution 5

$string="one two three four five";

list($second,$first) = explode(' ',strrev($string),2);
$first = strrev($first);
$second = strrev($second);

var_dump($first);
var_dump($second);

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Comments

[James]

Logically, as OP is using strings and not using arrays, I'd say use the "non" array option as they don't need an array (makes the code seem more logical as it's just working with a string) but is there any performance difference?