How to Find a Substring from a Given String?

To find a substring in a given string, you can use the strpos() function. If you call strpos($haystack, $needle), it will try to find the position of the first occurrence of the $needle string in the $haystack string. If found, it will return a non-negative integer represents the position of $needle. Othewise, it will return a Boolean false. Here is a PHP script example of strpos():

<?php
$haystack1 = "2349534134345fyicenter16504381640386488129";
$haystack2 = "fyicenter234953413434516504381640386488129";
$haystack3 = "center234953413434516504381640386488129fyi";
$pos1 = strpos($haystack1, "fyicenter");
$pos2 = strpos($haystack2, "fyicenter");
$pos3 = strpos($haystack3, "fyicenter");
print("pos1 = ($pos1); type is " . gettype($pos1) . "\n");
print("pos2 = ($pos2); type is " . gettype($pos2) . "\n");
print("pos3 = ($pos3); type is " . gettype($pos3) . "\n");
?>

This script will print:

pos1 = (13); type is integer
pos2 = (0); type is integer
pos3 = (); type is boolean

"pos3" shows strpos() can return a Boolean value.

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