Finding substrings and removing unwanted whitespace are everyday tasks. PHP provides purpose-built functions for both.
strpos() returns the position (0-based) of the first occurrence, or false if not found.str_contains() (PHP 8+) returns a boolean — cleaner for simple checks.trim() strips whitespace from both ends; ltrim() / rtrim() strip from the left or right only.Always use strict comparison (!== false) with strpos() because a match at position 0 is falsy.
<?php
$email = ' user@example.com ';
// Trim whitespace
echo trim($email); // "user@example.com"
echo ltrim($email); // "user@example.com "
echo rtrim($email); // " user@example.com"
$haystack = 'The quick brown fox';
// strpos — returns int|false
$pos = strpos($haystack, 'quick');
if ($pos !== false) {
echo "Found at position: $pos"; // 4
}
// str_contains — PHP 8+ boolean
if (str_contains($haystack, 'fox')) {
echo 'Fox is present';
}
// str_starts_with / str_ends_with (PHP 8+)
var_dump(str_starts_with($haystack, 'The')); // bool(true)
var_dump(str_ends_with($haystack, 'fox')); // bool(true)
Tip: str_contains(), str_starts_with(), and str_ends_with() were added in PHP 8.0 and make intent far clearer than the old strpos() !== false idiom.