How to Explode String Right to Left ?

Question

$split_point = ' - ';
$string = 'this is my - string - and more';

How can i make a split using the second instance of $split_point and not the first one. Can I specify somehow a right to left search? Best simple approach?

Basically how do I explode from Right to Left. I want to pick up the last instance of " - ".

Result I need:

$item[0]='this is my - string'; $item[1]='and more';

and not:

$item[0]='this is my'; $item[1]='string - and more';

Answer 1

If I understand correctly, you want the example case to give you ('this is my - string', 'and more')?

Built-in split/explode seems to be forwards-only - you'll probably have to implement it yourself with strrpos. (right-left search)

$idx = strrpos($string, $split_point);
$parts = array(substr($string, 0, $idx), substr($string, $idx+strlen($split_point)))

Answer 2

You may use strrev to reverse the string, and then reverse the results back:

$split_point = ' - ';
$string = 'this is my - string - and more';

$result = array_map('strrev', explode($split_point, strrev($string)));

Not sure if this is the best solution though.

Answer 3

Why not split on ' - ', but then join the first two array entries that you get back together?

Answer 4

How about this:

$parts = explode($split_point, $string);
$last = array_pop($parts);
$item = array(implode($split_point, $parts), $last);

Not going to win any golf awards, but it shows intent and works well, I think.

Answer 5

Assuming you only want the first occurrence of $split_point to be ignored, this should work for you:

# retrieve first $split_point position
$first = strpos($string, $split_point);
# retrieve second $split_point positon
$second = strpos($string, $split_point, $first+strlen($split_point));
# extract from the second $split_point onwards (with $split_point)
$substr = substr($string, $second);

# explode $substr, first element should be empty
$array = explode($split_point, $substr);

# set first element as beginning of string to the second $split_point
$array[0] = substr_replace($string, '', strpos($string, $substr));

This will allow you to split on every occurrence of $split_point after (and including) the second occurrence of $split_point.