PHP strpos to match querystring text pattern

Question

I need to execute a bit of script only if the $_GET['page'] parameter has the text "mytext-"

Querystring is: admin.php?page=mytext-option

This is returning 0:

$myPage = $_GET['page'];
$match = strpos($myPage, 'mytext-');
echo $match;

Answer 1

strpos returns the position of the string. Since it's 0, that means it was found at position 0, meaning, at the start of the string.

To make an easy way to understand if it's there, add the boolean === to an if statement like this:

<?php

$myPage = $_GET['page'];
$match = strpos($myPage, 'mytext-');

if ( $match === false ) {
    echo 'Not found';
} else {
    echo 'Found';
}

?>

This will let you know, if the string is present or not.

Or, if you just need to know, if it's there:

$myPage = $_GET['page'];
$match = strpos($myPage, 'mytext-');

if ( $match !== false ) {
    echo 'Found';
}

?>

Answer 2

Use substr() once you get the location of 'mytext-', like so:

$match = substr($myPage, strpos( $myPage, 'mytext-') + strlen( 'mytext-'));

Otherwise, strpos() will just return the numerical index of where 'mytext-' starts in the string.

You can also use str_replace() to accomplish this if your string only has 'mytext-' once:

$match = str_replace( 'mytext-', '', $myPage);