isset.php
<?php
if( isset($_GET['user']) ){
echo ' welcome to the website ' . $_GET['user'];
}
?>
测试 ： http://localhost/isset.php?user=zxl
add.php
<html>
<body>
<form action="add.php" method="GET">
<input type="number" size="5" name="num1" >
<input type="number" size="5" name="num2" >
<input type="submit" value="ADD" >
</form>
<?php
if( isset($_GET['num1']) and isset($_GET['num2']) ){
$num1 = $_GET['num1'];
$num2 = $_GET['num2'];
$total = $num1 + $num2;
echo 'the total is ' . $total;
}
?>
</body>
</html>
