字符串长度问题[关闭]

I have four string length statements I am trying to validate,but only two are working.

$name = "mike";
$age = "54";
$city = "Chicago";
$building = "Madadnock";
$lengthOfString1 = strlen ( $name );
echo "String length of 'name' " . $lengthOfString1  . "</br>";

$lengthOfString2 = strlen ( $age );
echo "String length of 'age' " . $lengthOfString2  . "</br>";
$lengthOfString3 = strlen ( $city );
echo "String length of 'city' " . $lengthOfstring3  . "</br>";

$lengthOfString4 = strlen ( $building );
echo "String length of 'building' " . $lengthOfstring4  . "</br>";

The top two are the only ones that work. Any help would be great!

variables in PHP are case sensitive

$lengthOfString4 vs $lengthOfstring4
         ^                   ^

The problem lies in variable names. The variable names in PHP are case-sensitive.

$lengthOfString3 = strlen ( $city );
echo "String length of 'city' " . $lengthOfString3  . "</br>";

$lengthOfString4 = strlen ( $building );
echo "String length of 'building' " . $lengthOfString4  . "</br>";

Fixed it.