Check if a variable is of function type

Question

Suppose I have any variable, which is defined as follows:

var a = function() {/* Statements */};

I want a function which checks if the type

Answer 1

@grandecomplex: There's a fair amount of verbosity to your solution. It would be much clearer if written like this:

function isFunction(x) {
  return Object.prototype.toString.call(x) == '[object Function]';
}