How to get the last occurrence of a string? - php

Question

I have a function that extracts the content between a $start and $end inside a $string
function get_string_between($string, $start, $end){
$string = " ".$string;
$ini = strpos($string,$start);
if ($ini == 0) return "";
$ini += strlen($start);
$len = strpos($string,$end,$ini) - $ini;
return substr($string,$ini,$len);
}
The problem with this is that it will only get me the first occurrence found in the string. Per example:
$text = "John has 13 oranges and Jane has 8 oranges";
$how_many_oranges = get_string_between($text,"has "," oranges");
echo $how_many_oranges; // echos "13"
I need it to find the last occurrence inside the string, so that $how_many_oranges = "8";

Answer 1

As mentioned in my comment, swap out strpos() for strrpos()
Find the numeric position of the last occurrence of needle in the haystack string.
Also, I believe you should change
if ($ini == 0)
to
if ($ini === false)
The former will match if $start is at the very beginning of $string. The latter will match if $start cannot be found at all.
Demo ~ https://eval.in/1027283

Answer 2

What about using just PHP's built in function?!
strripos() – Finds the position of the last occurrence of a string inside another string. It is a Case-insensitive.
PHP Docs

Answer 3

I took the liberty to rewrote your code, to make it, IMHO, more readable and self-explanatory :)
I'd also recommend you to use the strrpos:
function getStringBetween($string, $start, $end) {
$lastStartIndex = strrpos($string, $start);
$lastEndIndex = strrpos($string, $end);
$substringStartIndex = $lastStartIndex + strlen($start);
$substringSize = $lastStartIndex - $lastEndIndex - 1;
return substr($string, $substringStartIndex, $substringSize);
}
$text = "John has 13 oranges and Jane has 8 oranges";
$how_many_oranges = getStringBetween($text, "has", "oranges");
echo "'" . $how_many_oranges . "'"; // echos "' 8 '"

Answer 4

Try this:
function get_string_between($string, $start, $end){
$p1 = explode($start,$str);
for($i=1;$i<count($p1);$i++){
$p2 = explode($end,$p1[$i]);
$p[] = $p2[0];
}
return $p;
}
source: stackoverflow.com/a/45033158

Answer 5

This looks like a reasonable time to use regular expressions.
function get_string_between($string, $start, $end) {
$clean_start = preg_quote($start, '/');
$clean_end = preg_quote($end, '/');
$pattern = "/.*$clean_start (.*) $clean_end.*/U"; // U modifier => ungreedy
$default_result = ''; // returned if no matches found
$matches;
preg_match_all($pattern, $string, $matches);
return (count($matches[1]) > 0) ? end($matches[1]) : $default_result;
}
echo get_string_between('John has 13 oranges and Jane has 8 oranges', 'has', 'oranges'); // 8