The difference between the usage of stripslashes and addslashes in php_PHP tutorial

In PHP we often use stripslashes and addslashes. Let me introduce in detail how to use stripslashes and addslashes and the differences between them.

addslashes

The addslashes() function adds a backslash before the specified predefined characters.

These predefined characters are:

•Single quote (')
•Double quotes (")
•Backslash ()
•NULL

In this example, we want to add a backslash to a predefined character in a string:

Note: By default, the PHP instruction magic_quotes_gpc is on, automatically running addslashes() for all GET, POST and COOKIE data. Do not use addslashes() on strings that have been escaped by magic_quotes_gpc, as this will result in double escaping. When encountering this situation, you can use the function get_magic_quotes_gpc() to detect it.

} return $str;

The code is as follows

代码如下

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/** * 判断是否用addslashes()处理 * * @param String $str * */ function str_addslashes($str, $db_type='mysql') { if(get_magic_quotes_gpc()){    switch($db_type){            case "access": $str = stripslashes($str); $str = str_replace("'","''",$str);            break;        } }else {          switch($db_type){ case "mysql": $str = addslashes($str); break; case "access": $str = str_replace("'","''",$str); break;        }  } return $str; }

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/** * Determine whether to use addslashes() to process *

* @param String $str

*

*/

function str_addslashes($str, $db_type='mysql') { if(get_magic_quotes_gpc()){

switch($db_type){                                          case "access":

$str = stripslashes($str);

$str = str_replace("'","''",$str);      

代码如下	复制代码
//提交数据，或者变量准备： $Content=addslashes(”这里面是数据，不管有没单引号或者还是变量”); //插入数据到数据库，代码省略 //开始显示数据 $Content=”从数据库读取的数据”; if(get_magic_quotes_gpc()){   $Content=stripslashes($Content); } echo $Content;

break; 

} }else {            switch($db_type){

case "mysql":

$str = addslashes($str);

break;

case "access":

$str = str_replace("'","''",$str);

break; 

}

}

Custom function str_addslashes description: If we don’t know whether magic_quotes_gpc is turned on during the submission process, we can handle it in this way. When it is on, the mysql database will not be processed, but the access database still needs to be removed first, and then Single quotes are replaced with double quotes. Add to the mysql database when it is off stripslashes() The stripslashes() function removes backslashes added by the addslashes() function. Example

Code

The code is as follows

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//Submit data, or prepare variables: $Content=addslashes("This is data, whether there are single quotes or variables"); //Insert data into the database, code omitted //Start displaying data $Content="Data read from database"; if(get_magic_quotes_gpc()){ $Content=stripslashes($Content); } echo $Content; Summary of differences When magic_quotes_gpc = On, the data processed using addslashes() will be saved in the database in the form of '. If you output it directly at this time, you will find that there are more contents than you expected, so stripslashes() appears, it can be removed (different from str_replace("", "",$Str)). When magic_quotes_gpc = Off, the data processed using addslashes() will be saved in the database in the form of '. There is no problem mentioned above. addslashes() plays the role of inserting data without errors. If at this time If output directly, the data is normal. No need to use stripslashes() anymore. addslashes() and stripslashes() are exactly the opposite. Direct memory: addslashes() adds one, stripslashes() removes one http://www.bkjia.com/PHPjc/628898.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/628898.htmlTechArticleWe often use stripslashes and addslashes in php. Let me introduce in detail how to use stripslashes and addslashes. The difference between them. addslashes addslashes() function...