Concisely checking the length of a trimmed string

 
<?
if (strlen(trim("12345")) != 5) {
    print "Please enter a ZIP code that is 5 characters long.";
}
?>

1.	Calculating the length of a string
2.	Checking String Length
3.	Checking String Length: int strlen ( string string )
4.	strlen.php
5.	int strlen ( string str ) returns the number of characters in it:

Concisely checking the length of a trimmed string : strlen « String « PHP