PHP: Get string between two character with specific index

Question

I am a beginner of PHP. I have string:

$fullstring = "this is [tag]dog[/tag], [tag]cat[/tag], [tag]lion[/tag]";

I want to get string "cat" from my $fullstring.

I used to try with this:

Get substring between two strings PHP

But I can only get the first string (dog). Thank you for your time.

Thet Cartter.

I want to get only "cat" – Thet Cartter Jun 23 '16 at 08:05 — Thet Cartter, Jun 23 '16 at 08:05

Nergal · Answer 1 · 2020-08-03T12:21:47.147

Disclaimer: Both solution is naive. You should always check the returned value of preg_match_all and strpos.

Readable regex solution:

Try to use preg_match_all

$fullstring = "this is [tag]dog[/tag], [tag]cat[/tag], [tag]lion[/tag]";

preg_match_all("'\[tag\](.*?)\[\/tag\]'si", $fullstring, $match);

foreach($match[1] as $val){
    echo $val, ' ';
}
// result: dog cat lion

To get only the content of the second tag (which is cat now)

echo $match[1][1]
// result: cat

Not readable string split solution:

$fullstring = 'this is [tag]dog[/tag], [tag]cat[/tag], [tag]lion[/tag]';

function get_strings_between(string $string, string $start, string $end): array {
    $r = [];
    $startLen = strlen($start);
    $endLen = strlen($end);
    while (!empty($string)) {
        $startPosition = strpos($string, $start);
        if ($startPosition === false) {
            return $r;
        }
        $contentStart = $startPosition + $startLen;
        $contentEnd = strpos($string, $end, $contentStart);
        $len = $contentEnd - $contentStart;
        $r[] = substr($string, $contentStart, $len);
        $endPosition = $contentEnd + $endLen;
        $string = substr($string, $endPosition);
    }
    return $r;
}

$match = get_strings_between($fullstring, '[tag]', '[/tag]');
// result: dog cat lion

To get only the content of the second tag (which is cat now)

echo $match[1]
// result: cat

I was about to post exactly same answer. Here's a test I did http://www.phpliveregex.com/p/g9V It's slightly other pattern, but anyway exact pattern may differ depending on OP case. — Jakub Matczak, Jun 23 '16 at 08:05

Matthew Carpenter · Answer 2 · 2016-06-23T08:13:39.143

0

You're looking for preg_match() function. An example below may help you out.

 $fullString = "this is [tag]dog[/tag], [tag]cat[/tag], [tag]lion[/tag]";
 $regex = "/\[tag\]\w+\[\\tag\]/";
 preg_match($regex, $fullString, $matches);
 foreach($matches as $match){
     echo $match;
 }
 // result, dog, cat, lion

edited Jun 23 '16 at 08:13

answered Jun 23 '16 at 08:04

Matthew Carpenter

660
6
9

score 0 · Answer 3 · edited May 23 '17 at 12:34

This is a modified version of this answer. This function will return all instances it can find based on what you want to search.

    function getContents($str, $startDelimiter, $endDelimiter, $needle) {
    $contents = array();
    $startDelimiterLength = strlen($startDelimiter);
    $endDelimiterLength = strlen($endDelimiter);
    $startFrom = $contentStart = $contentEnd = 0;
    while (false !== ($contentStart = strpos($str, $startDelimiter, $startFrom))) {
        $contentStart += $startDelimiterLength;
        $contentEnd = strpos($str, $endDelimiter, $contentStart);
        if (false === $contentEnd) {
            break;
        }
        $tempString = substr($str, $contentStart, $contentEnd - $contentStart);
        if ($tempString == $needle) {
            $contents[] = $tempString;
        }
        $startFrom = $contentEnd + $endDelimiterLength;
    }

    return $contents;
}

to use: getContents($fullstring,'[tag]','[/tag]','cat'); // will return all instances of cat in the string — silverstrike, Jun 23 '16 at 08:14

score 0 · Answer 4 · edited Aug 14 '20 at 13:03

I try to modify the old function [http://www.justin-cook.com/wp/2006/03/31/php-parse-a-string-between-two-strings/]. I got this:

function get_string_between($string, $start, $end, $index){
    if ($index <= 0) return '';
    $string = ' ' . $string;
    $ini = 0;
    $x = 1;
    while ($x <= $index) {
      $ini = strpos($string, $start, $ini + 1);
      if ($ini == 0) return '';
      $x++;
    }
    $ini += strlen($start);
    $len = strpos($string, $end, $ini) - $ini;
    return substr($string, $ini, $len);
}

$fullstring = "this is [tag]dog[/tag], [tag]cat[/tag], [tag]lion[/tag]";
echo get_string_between($fullstring, "[tag]", "[/tag]", 2); // Result = cat

PHP: Get string between two character with specific index

4 Answers4

Readable regex solution:

Not readable string split solution: