Accurately check if a string contains a phrase

examples.php

<?php
$string = 'Hello world!';
$phrase = 'He';

if ( strpos( $string, $phrase ) ) {
	// This code won't run.
}

if ( cameronjonesweb_string_contains_phrase( $string, $phrase ) ) {
	// This code will run.
}

function.php

<?php
/**
 * Searches for a phrase in a given string
 *
 * @param string $haystack The haystack to search.
 * @param string $needle The needle to search for.
 * @return bool Whether the needle was found or not
 */
function cameronjonesweb_string_contains_phrase( $haystack, $needle ) {
	// As strpos will return 0 if the string begins with the phrase, we need to do an is_numeric check
	return is_numeric( strpos( $haystack, $needle ) );
}