How Do I Check if a String Contains a Specific Word in PHP?

How to Determine if a String Contains a Particular Word

In programming, it is often necessary to check whether a string contains a specific word or substring. One common way to do this is using the if statement, as demonstrated in your code excerpt:

$a = 'How are you?';

if ($a contains 'are')
    echo 'true';

However, the code above won't work because there is no built-in "contains" method for strings in PHP. To correctly write this statement, we can use alternative methods.

PHP 8 and Later

PHP 8 introduces the str_contains function, which simplifies checking for substring existence:

if (str_contains('How are you', 'are')) {
    echo 'true';
}

Before PHP 8

Prior to PHP 8, you can use the strpos() function to find the occurrence of a substring:

$a = 'How are you?';
$needle = 'are';

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

Here, strpos() searches for the position of the substring, and a non-false result indicates its presence.

Additional Notes

• The str_contains function is case-sensitive. To perform a case-insensitive search, you can first convert both strings to the same case.
• The strpos() function returns 0 if the substring appears at the beginning of the string.
• You can use the empty($needle) check to avoid empty substring matches.

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