w3school的PHP教程提炼(一)PHP基础

本笔记只提炼php需要注意的部分，关于运算符，简单判断等内容一概不写。

1 字符串

1.1 strlen()函数计算字符串长度

php echo strlen ( " hello world! " ); ?>

1.2 strops()函数在字符串内检索字符串或字符

php echo strpos ( " hello world " , " world " ); ?>

2 数组

2.1 数值数组 带有数字ID键的数组

自动分配ID键：

$names = array ( " a " , " b " , " c " );

人工分配ID键：

$names [ 0 ] = " a " ; $names [ 1 ] = " b " ; $names [ 2 ] = " c " ;

使用ID键：

php echo $names [ 0 ] . " & " . $names [ 1 ] . " & " . $names [ 2 ]; ?>

2.2 关联数组 数组中的每个ID键关联一个值

将值作为键分配：

$ages = array ( " a " => 10 , " b " => 20 , " c " => 30 );

另一种方法：

$ages [ " a " ] = " 10 " ; $ages [ " b " ] = " 20 " ; $ages [ " c " ] = " 30 " ;

使用ID键：

php echo " a is " . $ages [ " a " ] . " years old. " ; ?>

2.3 多维数组 包含一个或多个数组的数组(略)

3 循环

3.1 while

php $i = 1 ; while ( $i <= 5 ){ echo " the number is " . $i . "

" $i ++ ;} ?>

3.2 do...while

php $i = 0 ; do { $i ++ ; echo " the number is " . $i . "

" ;} while ( $i < 5 ); ?>

3.3 for

php for ( $i = 1 ; $i <= 5 ; $i ++ ){ echo " hello world!

" ;} ?>

3.4 foreach

foreach语句用于循环遍历数组，每进行一次循环，当前数组元素的值就会被赋值给value变量(数组指针会逐一地移动)以此类推。

语法

foreach ( array as value){ // ... }

示例：输出给定数组的值

php $arr = array ( " one " , " two " , " three " ); foreach ( $arr as $value ){ echo " value: " . $value . "

" ;} ?>

4 函数

4.1 传递参数

php function writeName( $firstname , $lastname ){ echo $firstname . $lastname . "

" ;} echo " my name is " ;writeName( " Gang " , " Li " ); echo " my name is " writeName( " San " , " Zhang " ); ?>

4.2 返回值

php function add( $x , $y ){ $total = $x + $y ; return $total ;} echo " 1 + 2 = " . add( 1 , 2 ); // print 1 + 2 = 3 ?>

5 表单处理

$_GET变量用于收集来自method="get"的表单的值。

$_POST变量用于收集来自method="post"的表单的值。

5.1 $_GET变量

form.php

< form action ="welcome.php" method ="get" > Name: < input type ="text" name ="name" /> Age: < input type ="text" name ="age" /> < input type ="submit" /> form >

welcome.php

Welcome php echo $_GET [ " name " ]; ?>.< br /> You are php echo $_GET [ " age " ]; ?> years old !

5.2 $_POST变量

与$_GET不同之处在于：

$_POST没有发送信息量限制，而$_GET限制100字符

$_POST不在url处体现表单中的值，而$_GET传递的url可以加入收藏夹

5.3 $_REQUEST变量

$_REQUEST变量可用来取得通过get和post方法发送到表单数据的结果 本条技术文章来源于互联网，如果无意侵犯您的权益请点击此处反馈版权投诉 本文系统来源：php中文网