void unset($var1[, $var2...]);

$varx - the list of variables to set as undefined

After this function is used on a variable, such as $name1, isSet($name1) will return 0. Accesses to the variable name will fail because it will no longer be assigned a value.

If a variable name in the list is already undefined (unset), then the function has no effect on the undefined variable name.

Example: To remove a variable named $varname from memory, use unset($varname), DO NOT use unset('varname').

It is recommended that this function be used instead of unDefine().

This function is supported by CSE HTML Validator v11.9910 and later.