Posted By
Bajarangi soft ,
Posted On 22-09-2020
Syntax for PHP isset() Function.
isset(variable1, variable2....);
Parameter Description
variable1 Specifies the variable to check
variable2 Specifies the variable to check and its optional
... Optional. Another variable to check
Example(1)
<?php
$variable1 = "test";
// True because $variable1 is set
if (isset($variable1)) {
echo "Variable1 is set.";
}
$variable2 = null;
// False because $variable2 is NULL
if (isset($variable2)) {
echo "Variable2 is set.";
}
?>
In above example we created two variables.In $variable1 we stored "test " and in $variable2 we stored "null" when variables checks in isset function condition we get know variable is null or not.
Complete code of isset() function.
<!DOCTYPE html>
<html>
<head>
<title>What does isset function in PHP</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css">
</head>
<body>
<div class="container">
<br>
<br>
<br>
<div class="text-center">
<h1>PHP isset() Function</h1>
</div>
<br>
<br>
<h2></h2>
<div class="well">
<?php
$variable1 = "test";
// True because $variable1 is set
if (isset($variable1)) {
echo "<h1>Variable1 is set.</h1>";
}
$variable2 = null;
// False because $variable2 is NULL
if (isset($variable2)) {
echo "<h1>Variable2 is set.</h1>";
}
?>
</div>
<br>
</div>
</body>
</html>