What is the usage of the addslashes function in PHP?
The addslashes function is a string processing function in PHP that adds a backslash before certain special characters to prevent them from being misinterpreted as having special meaning.
The syntax of the function is as follows:
string addslashes ( string $str )
Explanation of parameters:
- string: the string to be escaped.
The function works by adding a backslash before the specified special characters.
- Single quotation mark (‘)
- quotation marks
- backslash (\)
- The null character (\0)
- Carriage return ( \r )
- line break character (“\n”)
- Horizontal tabulation character (\t)
- Control characters with ASCII values from 0 to 31.
Using the addslashes function can escape special characters in a string before inserting it into a database or writing SQL statements, thereby avoiding security issues like SQL injection. However, it is important to note that the addslashes function cannot completely prevent SQL injection, as different encoding characters may have different handling results. Therefore, it is recommended to use more secure methods in practice, such as using prepared statements or SQL parameter binding.
