AngularJS introspection utilities


AngularJS ships with various functions to check types, such as angular.isNumber(), angular.isUndefined(), and angular.isElement(). This extension adds many functions to AngularJS' builtins, including a general-purpose type-checking function and a cloning function.

This is particularly useful if you want the type-checking functionality of Lo-Dash or Underscore, but without the libraries themselves. Many of these functions were derived from Lo-Dash implementations.

Type-Checking Functions

Each of these functions accept a value and return a boolean.

  • isNull() / isNotNull()
  • isBoolean() / isNotBoolean()
  • isNaN() / isNotNaN()
  • isFinite() / isNotFinite()
  • isInfinite() / isNotInfinite()
  • isArguments() / isNotArguments()
  • isRegExp() / isNotRegExp()
  • isEmpty() / isNotEmpty()
  • isInteger() / isNotInteger()
  • isFloat() / isNotFloat()
  • isObjectish() / isNotObjectish() (returns true if the value is not null and may contain properties)

In addition, the negation of the AngularJS built-ins are provided:

  • isNotUndefined()
  • isNotArray()
  • isNotDate()
  • isNotElement()
  • isNotObject()
  • isNotString()
  • isNotFunction()
  • isNotNumber()


The type() function will accept a value and return one of the following strings:

null, string, array, date, regexp, arguments, boolean, number, undefined, function, element, object

An element is considered to be a DOM node, jqLite object, or jQuery object.


The clone() function will return a deep clone of some value. This differs from angular.copy() in the following ways:

  • Simply returns the cloned value; does not accept a destination parameter.
  • Works on DOM nodes, jqLite elements or jQuery objects.
  • If a nested value implements a clone() function, that function will be called. This is useful for complex nested objects.
  • Calls angular.copy() internally so your $$hashKeys are not befouled.
  • Accepts an optional second Object parameter, extra, which can be extended onto the clone. This is useful, for example, if you have a unique identifier in an object, and wish to re-generate it.

Usage (Browser)

In the browser, if not using AMD, the functions are attached to the angular object as to not further pollute the global scope.

Usage (CommonJS/NodeJS)

In a NodeJS context, require() the angular-types module.

Usage (AMD/RequireJS)

Using RequireJS, just require types.


If using in NodeJS (a la Browserify):

Otherwise, use Bower:


Christopher Hiller


Copyright © 2014 Decipher, Inc. Licensed MIT

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This page was last updated over 2 years ago.