php 常用函数(一)

addslashes() 函数返回在预定义字符之前添加反斜杠的字符串。
预定义字符是：单引号（’）,双引号（”）,反斜杠（\）,NULL
例如

<?php
$str = "Who's Bill Gates?";
echo $str . " This is not safe in a database query.<br>";
echo addslashes($str) . " This is safe in a database query.";
?>  

输出

Who's Bill Gates? This is not safe in a database query.
Who\'s Bill Gates? This is safe in a database query.

addcslashes()函数:在指定字符串前加反斜杠

<?php
$str = "Welcome to Shanghai!";
echo $str."<br>";
echo addcslashes($str,'a')."<br>";
echo addcslashes($str,'S')."<br>";
?>

输出

Welcome to Shanghai!
Welcome to Sh\angh\ai!
Welcome to \Shanghai!