To check whether a variable is set in PHP, you can use the isset()
function. This function returns true
if the variable is set, and false
otherwise.
A variable is considered set if it has been assigned a value, even if the value is null
.
For example:
$var = '';
if (isset($var)) {
echo '$var is set';
} else {
echo '$var is not set';
}
This would output $var is set
.
You can also use the empty()
function to check whether a variable is set and is not null
. This function returns true
if the variable is set and is not null
, and false
otherwise.
For example:
$var = '';
if (empty($var)) {
echo '$var is empty';
} else {
echo '$var is not empty';
}
This would output $var is not empty
.