how to check if a letter exists in a string php code example

Example 1: php check if string contains word

$myString = 'Hello Bob how are you?';
if (strpos($myString, 'Bob') !== false) {
    echo "My string contains Bob";
}

Example 2: if part of stringp ph

$a = 'How are you?';

if (strpos($a, 'are') !== false) {
    echo 'true';
}

Example 3: How do I check if a string contains a specific word?

$a = 'Hello world?';

if (strpos($a, 'Hello') !== false) { //PAY ATTENTION TO !==, not !=
    echo 'true';
}
if (stripos($a, 'HELLO') !== false) { //Case insensitive
    echo 'true';
}

Example 4: if text contains word then in php

if (strpos($haystack,$needle) !== false) {
    echo "$haystack contains $needle";
}

Example 5: php check if string contains a char

$haystack = 'This is my haystack that we shall check'
$has_A = strpos($haystack, 'A') !== false;
$has_a = strpos($haystack, 'a') !== false;