The array_map function can be used to get the length and the max function can be used to get the length of the longest string.
Below is a code sample for the same −
$max_len = max(array_map('strlen', $array));Example
$array = array("a", "Ab", "abcd", "abcdfegh", "achn");
$max_len = max(array_map('strlen', $array));
echo $max_len;Output
This will produce the following output −
8