Question

Is there any way I can pass a primitive data type into a function parameter (or equivalently, store it into a variable) in PHP? By primitive types I mean int, bool, double, string, etc.

More specifically, I would like to do something like this:

function SomeFunc($DataType, $SomeOtherPara)
{
}

SomeFunc(int, "test1");
SomeFunc(bool, "test2");

A possible usage might be:

//! Cast the input parameter into a data type, recursively.
/*!
    \param[in]  $DataType            Data type, e.g. int, double, bool, string.
    \param[in]  $InputPara           Any input parameter.
*/
function TypeJuggleRecursive($DataType, $InputPara)
{
    if(is_array($InputPara))
    {
        // Work on each array element recursively.
        $ReturnPara = array();
        foreach($InputPara as $Key => $Value)
        {
            $ReturnPara[$Key] = TypeJuggleRecursive($DataType, $Value);
        }
        return $ReturnPara;
    }
    else
    {
        // Cast to data type.
        return ($DataType)$InputPara;
    }
}

TypeJuggleRecursive(bool, $_GET);
TypeJuggleRecursive(int, $_POST);

An obvious workaround would be to use strings instead, i.e. "string" for string, "int" for int, etc., but that seems dumb.

Answer 1

If it was a dumb way to do it, I don’t think settype() would use a string 🙂

http://php.net/manual/en/function.settype.php