34 lines
841 B
PHP
34 lines
841 B
PHP
<?php
|
|
// Check to see whether it is defined
|
|
if (!isset($var))
|
|
echo "var is undefined at first check\n";
|
|
|
|
// Give it a value
|
|
$var = "Chocolate";
|
|
|
|
// Check to see whether it is defined after we gave it the
|
|
// value "Chocolate"
|
|
if (!isset($var))
|
|
echo "var is undefined at second check\n";
|
|
|
|
// Give the variable an undefined value.
|
|
unset($var);
|
|
|
|
// Check to see whether it is defined after we've explicitly
|
|
// given it an undefined value.
|
|
if (!isset($var))
|
|
echo "var is undefined at third check\n";
|
|
|
|
// Give the variable a value of 42
|
|
$var = 42;
|
|
|
|
// Check to see whether the it is defined after we've given it
|
|
// the value 42.
|
|
if (!isset($var))
|
|
echo "var is undefined at fourth check\n";
|
|
|
|
// Because most of the output is conditional, this serves as
|
|
// a clear indicator that the program has run to completion.
|
|
echo "Done\n";
|
|
?>
|