PHP 简单学习  1. 为什么要学习PHP 2. PHP语法 3. php 变量 4. 字符串数据 5. PHP 函数 6. 数组   
 
php存量多 开源软件多 很多安全流程 渗透方法 sql注入基于PHP语言 入门简单 格式: <?php 内容?>或<?内容?> 结尾分号 例子<?php 
phpinfo ( ) ; 
? > 
 可变变量: $变量名 = 赋值内容<?php 
header ( 'Content-type:text/html;charset=utf-8' ) ; 
$shu  =  ‘biao’;
$biao  =  ‘鼠标’;
echo  $$shu ; 
? > 
 外部变量: 一些已经定义好的表示特定内容的变量< html> < head> </ head> < body> < formaction = " req.php" method = " post" > < inputtype = " text" name = " username" /> < inputtype = " password" name = " pwd" /> < inputtype = " submit" name = " 提交" /> </ form> </ body> </ html> <?php 
$u  =  $_POST [ 'username' ] ; 
echo  $u . '<br />' ; 
$passwd  =  $_POST [ 'pwd' ] ; 
echo  $passwd . '<br />' ; 
? > 
 单引号: 单纯文本输出不会解析文本中的变量但是效率高 双引号: 输出文本内容但是会解析 < html> < head> < title> </ title> </ head> < body> < formaction = " glob.php" method = " post" > < inputtype = " text" name = " hongniu" /> < br/> < inputtype = " submit" value = " 提交" /> </ form> </ body> </ html> <?php 
function  demo ( ) { echo  $_POST [ 'hongniu' ] ; 
} 
demo ( ) ; 
? > 
数组的定义方法<?php 
$shu  =  array ( 1  ,  1.5  ,  true  , '天王盖地虎,小鸡炖蘑菇' , '老男孩的学生最牛逼' ) ; 
echo  '<pre>' ; 
var_dump ( $shu ) ; 
echo  '</pre>' ; 
? > 
 循环输出数组 普通循环输出数组echo  "for each 数组例子:" . "<br>" ; 
$array  =  [ 'oldboy' ,  'oldgirl' ,  'littleboy' ] ; 
foreach  ( $array  as  $value ) { echo  "值是:"  .  $value ; echo  "<br/>" ; 
} 
for each 数组例子:
值是:oldboy
值是:oldgirl
值是:littleboy
 带着key值输出foreach  ( $array  as  $key  =>  $value )  { echo  "键名是:"  .  $key  .  ",值是:"  .  $value ; echo  "<br/>" ; 
} 
键名是:0,值是:oldboy
键名是:1,值是:oldgirl
键名是:2,值是:littleboy
 制定分割内容输出echo  "explode(),把字符串分割为数组例子:" . "<br>" ; 
$str  =  "I am oldboy, I like girls" ; print_r ( explode ( " " , $str ) ) . "<br/>" ; 
explode(),把字符串分割为数组例子:
Array ( [0] => I [1] => am [2] => oldboy, [3] => I [4] => like [5] => girls ) 
$row = explode ( " " , $str ) ; 
foreach  ( $row  as  $value ) { echo  "值是:"  .  $value ; echo  "<br/>" ; 
值是:I
值是:am
值是:oldboy,
值是:I
值是:like
值是:girls