<?php
$mystring = 'abc';
$findme   = 'a';
$pos = strpos($mystring, $findme);
// The !== operator can also be used.  Using != would not work as expected
// because the position of 'a' is 0. The statement (0 != false) evaluates
// to false.
if ($pos !== false) {
     echo "The string '$findme' was found in the string '$mystring'";
         echo " and exists at position $pos";
} else {
     echo "The string '$findme' was not found in the string '$mystring'";
}

//Find the position of the first occurrence of a substring in a string
$mystring = 'abc';
$findme = 'a';
$pos = strpos($mystring, $findme);

$pos = strpos("find the position of X in here", "X");

strpos('STRING', 'SEARCH_ITEM');
--------------OR--------------------
preg_match('~' . preg_quote('.SEARCH_ITEM.', '~') . '~', 'STRING');

// Declaring a string variable
$string = "Hello World";
// Getting the length of the string
$length = strlen($string);
echo "Length of the string: " . $length . "\n";
// Converting the string to uppercase
$uppercase = strtoupper($string);
echo "Uppercase string: " . $uppercase . "\n";
// Converting the string to lowercase
$lowercase = strtolower($string);
echo "Lowercase string: " . $lowercase . "\n";
// Replacing a substring within the string
$newString = str_replace("World", "Universe", $string);
echo "Replaced string: " . $newString . "\n";
// Checking if a string contains a substring
if (strpos($string, "Hello") !== false) { echo "The string contains 'Hello'\n";
} else { echo "The string does not contain 'Hello'\n";
}