PHP htmlspecialchars return null solve the problem

In the development, it is often necessary to pass over the user data is filtered to prevent some malicious user input in PHP used to htmlspecialchars(), htmlentities()and strip_tags()function to handle.

In use today htmlspecialchars()do special character conversion, has been returned null, when I replaced htmlentities()is the same problem, check the official manual I realized that coding problems.

Function declaration:

The main problem is on the third argument, the third argument for official says so:

This effect is the coding parameter used when converting character set used in the PHP 5.4 and 5.5 UTF-. 8 as a default encoding, prior to the use of 5.4 PHP the ISO-8859-1 as the default encoding, from the beginning uses the PHP PHP 5.6 profile default_charsetparameters as the default encoding. encodingParameters supported character sets:

From PHP update log you can also see a change in this parameter:

Generally, we are so used:

1 2 3

str = $ ' <a href="test.html"> ' big column  to solve the problem of the PHP htmlspecialchars return null ; test page ' </a> <Script> Alert ( 213 ) </ Script> '; echo htmlspecialchars ($ STR); // output: & lt ; A the href = & quot; the test.html & quot; & gt ; 'test page' & lt ; / A & gt ; & lt ; Script & gt ; Alert ( 213 ) & lt ; & / Script gt ;

Today, when in use, the results always return null, in fact, coding problems, this time you need to use the third argument:

1	echo htmlspecialchars($string, ENT_COMPAT,'ISO-8859-1', true);

The same also applies to htmlentities:

1	echo htmlentities($string, ENT_COMPAT,'ISO-8859-1', true);