Return string segment based on strings

Question

How would you return part of a string based on the contents of the string in php. Unlike substr() and related functions where you use an integer length

So if we are given a string like this here is a nice string that is being used as an example

How could we return a string like this

nice string

Somehow we have to pass the function a and that so it knows the start and end point. It will find the first a and then start keeping track of characters then when it finds that it will stop, and return.

To be clear: we know the contents of the original string... and the arguments sent.

Answer 1

Use this function:

function get_string_between($string, $start, $end)
{
    $ini = strpos($string,$start);
    if ($ini == 0)
        return "";
    $ini += strlen($start);
    $len = strpos($string,$end,$ini) - $ini;
    return substr($string,$ini,$len);
}

$input = 'here is a nice string that is being used as an example';
$output = get_string_between($input, 'a', 'that');
echo $output;  //outputs: nice string

Answer 2

You could use regular expressions too with preg_match:

<?php

function get_string_between($string,$start,$end) {
    preg_match("/\b$start\b\s(.*?)\s\b$end\b/",$string,$matches);
    return $matches[1];
}

$str = "here is a nice string that is being used as an example";
print get_string_between($str,"a","that")."\n";

?>