The strlen() function is used to return the length
of a string.
Let's find the length of a string:
<?php
echo strlen("Hello world!");
?>
The output of the code above will be:
12
The length of a string is often used in loops or other functions, when it is
important to know when the string ends. (i.e. in a loop, we would want to stop
the loop after the last character in the string).