typeOf()

An alternative to Javascript's "typeof" that provides more consistent results...

Syntax

typeOf() can be used as a global function, or as a method of any object...

var returnValue = typeOf(obj);
// or...
var returnValue = obj.typeOf();

Parameters

Parameter / Object Type Mandatory Description Util.js version

obj

Variant

By default, typeOf() will return the type of 'this' – the object that it is a method of.

If you pass in an object of any kind as a parameter, typeOf() will return the name of that object's constructor.

1.0

Return valye

Returns the string name of the constructor of the class from which the object was derived (or primitive value type coerced to).

Examples

Car must be taken when checking the type of primitive values...

// don't do this:
var returnValue = 5.typeOf(); // Syntax Error

// instead, do this:
var returnValue = typeOf(5); // "number"
var returnValue = (5).typeOf(); // "number"
 
// Or if you want a l33t way of doing it:
var returnValue = 5..typeOf(); // "number" (:

The following examples show the key differences between Javascript's typeof operator and the typeOf() function...

Availability

This feature requires:

Util.js v0.3 and above.
Can be accessed via global object/scope.

typeof {a: 4}; //"object"
typeof [1, 2, 3]; //"object"
(function() {return typeof arguments})(); //"object"
typeof new ReferenceError; //"object"
typeof new Date; //"object"
typeof /a-z/; //"object"
typeof Math; //"object"
typeof JSON; //"object"
typeof new Number(4); //"object"
typeof new String("abc"); //"object"
typeof new Boolean(true); //"object"

typeOf(stuff)

typeOf({a: 4}); //"object"
typeOf([1, 2, 3]); //"array"
(function() {return typeOf(arguments)})(); //"arguments"
typeOf(new ReferenceError); //"error"
typeOf(new Date); //"date"
typeOf(/a-z/); //"regexp"
typeOf(Math); //"math"
typeOf(JSON); //"json"
typeOf(new Number(4)); //"number"
typeOf(new String("abc")); //"string"
typeOf(new Boolean(true)); //"boolean"