PHP isset() Function
The PHP isset() function is always used in osCommerce codes.
The PHP isset() function will determine if a variable is set and is not NULL.
Notes for PHP isset() function:
- Returns TRUE if the variable exists and has value other than NULL.
- Remember that an empty string is not null.
- The result may sometimes expect differently with PHP version 4 and 5.
PHP isset() Function Example 1:
<?php
// The value of $cPath come from Hardware
$cPath = "1";
if (isset($cPath)) {
// if the $cPath variable is set and is not null, the codes here will be executed.
echo 'The value of $cPath is set and the value is: ' . $cPath;
} else {
// if the $cPath variable is NOT set, the codes here will be executed.
echo 'The value of $cPath is NOT set';
}
?>
The output of the above PHP isset() function example 1 should look like:
Thee value of $cPath is set and the value is: 1
PHP isset() Function Example 2:
<?php
// The value of $cPath come from osCommerce homepage.
// The value of $cPath is now empty.
$cPath = "";
if (isset($cPath)) {
// if the $cPath variable is set and is not null, the codes here will be executed.
echo 'The value of $cPath is set and the value is: ' . $cPath;
} else {
// if the $cPath variable is NOT set, the codes here will be executed.
echo 'The value of $cPath is NOT set';
}
?>
The output of the above PHP isset() function example 2 should look like:
The value of $cPath is set and the value is:
Although the value of $cPath is empty, the isset() function still return TRUE.
This is the end of PHP isset() function for osCommerce shop.