unset Unset a given variable voidunset mixedvar mixedvar mixed... unset destroys the specified variables. Note that in PHP 3, unset will always return &true; (actually, the integer value 1). In PHP 4, however, unset is no longer a true function: it is now a statement. As such no value is returned, and attempting to take the value of unset results in a parse error. ]]> The behavior of unset inside of a function can vary depending on what type of variable you are attempting to destroy. If a globalized variable is unset inside of a function, only the local variable is destroyed. The variable in the calling environment will retain the same value as before unset was called. ]]> The above example would output: If a variable that is PASSED BY REFERENCE is unset inside of a function, only the local variable is destroyed. The variable in the calling environment will retain the same value as before unset was called. ]]> The above example would output: If a static variable is unset inside of a function, unset destroys the variable and all its references. ]]> The above example would output: If you would like to unset a global variable inside of a function, you can use the $GLOBALS array to do so: ]]> ¬e.language-construct; See also isset, empty, and array_splice.