php实战手册（2）
目录
- 变量
- 接收表单数据
变量
- 定义
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>php demo</title>
</head>
<body>
<?php $x=11; ?>
<p>
php hello,world
</p>
<?php
//我是注释行
echo $x*$x;
/*
注释行1
注释行2
*/
?>
</body>
</html>
- 变量内插与null
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>php demo</title>
</head>
<body>
<p>
php hello,world
</p>
<?php
//我是注释行
$x=null;
if (is_null($x)){
echo '$x is null';
$x=22;
}
?>
<br/>
<?php
if ($x>11)
echo "$x >11";
else
echo $x*$x;
?>
</body>
</html>
接收表单数据
- 表单submit
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>php demo</title>
</head>
<body>
<p>
<form name="input_x_form" action="index.php" method="POST">
<label for="x">x:</label>
<input type="text" id="x" name="x" size="10" />
<button id="btn_ok" type="submit" >确定</button>
</p>
<?php
$x=$_POST["x"];
if (is_null($x)){
echo '$x is null';
$x=22;
}
?>
<br/>
<?php
if ($x>11)
echo "$x >11";
else
echo $x*$x;
?>
</body>
</html>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>php demo</title>
</head>
<body>
<form name="input_form" action="index.php" method="POST">
<p> <label>
Name:
<input type="text" id="name" name="name" required minlength="2" maxlength="8" size="10" />
</label>
<br/>
<label for="x">x:</label>
<input type="text" id="x" name="x" />
</p>
<p>
<button id="btn_ok" type="submit" >确定</button>
</p>
<?php
//我是注释行
$x=$_POST["x"];
$name=$_POST["name"];
echo "hello,$name<br/>";
if (is_null($x)){
echo '$x is null';
$x=22;
}
?>
<br/>
<?php
if ($x>11)
echo "$x >11";
else
echo $x*$x;
?>
</body>
</html>
- 使用js 提交
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>php demo</title>
</head>
<body>
<form name="input_form" action="index.php" method="POST">
<p> <label>
Name:
<input type="text" id="name" name="name" required minlength="2" maxlength="8" size="10" />
</label>
<br/>
<label for="x">x:</label>
<input type="text" id="x" name="x" />
</p>
<p>
<button id="btn_ok" type="button" onClick="get_data()">确定</button>
</p>
<script type="text/javascript">
function get_data(){
document.input_form.submit();
}
</script>
<?php
//我是注释行
$x=$_POST["x"];
$name=$_POST["name"];
echo "hello,$name<br/>";
if (is_null($x)){
echo '$x is null';
$x=22;
}
?>
<br/>
<?php
if ($x>11)
echo "$x >11";
else
echo $x*$x;
?>
</body>
</html>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>php demo</title>
</head>
<body>
<form name="input_form" action="index.php" method="POST">
<p> <label>
Name:
<input type="text" id="name" name="name" required minlength="2" maxlength="8" size="10" />
</label>
<br/>
<label for="x">x:</label>
<input type="text" id= "x" name="x" />
</p>
<p>
<button id="btn_ok" type="button" onclick="get_data()">确定</button>
</p>
<script type="text/javascript">
function get_data(){
let x=document.getElementById("x").value;
if (isNaN(Number(x))) {
document.getElementById("x").value=0;
alert("请输入正确的x");
}
document.input_form.submit();
}
</script>
<?php
//我是注释行
$x=$_POST["x"];
$name=$_POST["name"];
echo "hello,$name<br/>";
if ($x>11)
echo "$x >11";
else
echo "$x <=11";
?>
</body>
</html>
