PHP exact search

Question

So I have

$q = $_REQUEST["q"];
$f = fopen("address.txt", "r");
while (($line = fgets($f)) !== FALSE) {
   if (strstr($line, $q)) {
       print "<li>found: $line"; 

Lets say I have

Street 1 number 122
Street 2 number 22

in address.txt and I want to search for the number 22.

How to search for 22, but not to get 122 also?

Thanks in advance.

Answer 1

You could use a regex with word boundaries to accomplish this. Quick example:

if(preg_match('/\b22\b/', $line)) {

PHP Demo: https://eval.in/817207
Regex Demo: https://regex101.com/r/y9slbd/1/

Example using input (the $q):

if(preg_match('/\b' . preg_quote($q, '/') . \b/', $line)) {

http://php.net/manual/en/function.preg-quote.php

(Although your example of 22 shouldn't have caused any issues if concatenated into this example)