How to get a substring between two strings in PHP?

Answer 1

Consider this function. It accepts both position number, and strings arguments:

function get_string_between($string, $start = '', $end = ''){
    if (empty($start)) {
      $start = 0;
    }elseif (!is_numeric($start)) {
      $start = strpos($string, $start) + strlen($start);
    }

    if (empty($end)) {
      $end = strlen($string);
    }elseif (!is_numeric($end)) {
      $end = strpos($string, $end);
    }

    return substr($string, $start, ($end - $start));
  }

Results:

echo get_string_between($string); // result = this is my [tag]dog[/tag]
echo get_string_between($string, 0); // result = this is my [tag]dog[/tag]
echo get_string_between($string, ''); // result = this is my [tag]dog[/tag]
echo get_string_between($string, '[tag]'); // result = dog[/tag]
echo get_string_between($string, 0, '[/tag]'); // result = this is my [tag]dog
echo get_string_between($string, '', '[/tag]'); // result = this is my [tag]dog
echo get_string_between($string, '[tag]', '[/tag]'); // result = dog
echo get_string_between($string, '[tag]', strlen($string)); // dog[/tag]