How Can I Efficiently Check for Multiple Substrings in a PHP String?

Finding Multiple Substrings Using strpos and Arrays

In PHP, strpos is a commonly used function to search for the first occurrence of a substring within a given string. While it is capable of finding a single substring, there may be situations where you need to search for multiple substrings simultaneously.

In your specific example, you want to check whether all the elements in the $find_letters array exist within the $string variable. However, directly passing an array as the needle to strpos will not work as it expects a single value.

To address this, you can utilize a custom function that performs the task you need. Here's an updated version of the function provided as the answer:

function strposa(string $haystack, array $needles, int $offset = 0): bool
{
    foreach ($needles as $needle) {
        if (strpos($haystack, $needle, $offset) !== false) {
            return true; // Stop on the first true result
        }
    }

    return false;
}

In this function, we iterate through each element in the $needles array. For each element, we use strpos to check if it exists within the $haystack string, starting from the specified $offset position. If any of the elements matches, we return true immediately, indicating that the search is successful.

Usage example:

$string = 'This string contains word "cheese" and "tea".';
$array = ['burger', 'melon', 'cheese', 'milk'];

if (strposa($string, $array)) {
    echo 'true';
} else {
    echo 'false';
}

Output:

true

In this example, the function returns true because the string contains one of the elements in the array, namely "cheese."

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