jQuery type() Method

What Is type()?

jQuery.type(obj) (alias $.type) returns a lowercase string for the value’s internal JavaScript [[Class]] (added in jQuery 1.4.3). It is clearer than typeof for null, arrays, dates, and regexps.

$.type(value)  → lowercase type string

$.type(null)         → "null"
$.type([])           → "array"
$.type(new Date())   → "date"
$.type(/test/)       → "regexp"

typeof null          → "object"   // surprise!
typeof []            → "object"   // surprise!

How to Use type()

Pass any value, read the type string, then branch.

1. Start with a value whose kind you need to know.
2. Call $.type(value) to get a lowercase string.
3. Compare with === "array", === "null", and so on.
4. In new code, prefer native checks instead of $.type.

Pseudocode

function type(obj):
    if obj is undefined: return "undefined"
    if obj is null:      return "null"
    // use internal [[Class]] for built-ins
    return className.toLowerCase()   // "array", "date", ...

// Typical flow:
kind = $.type(input)
if kind === "array":
    loop items
else if kind === "null":
    handle missing value

Cheat Sheet

Keep these facts handy while classifying values with jQuery.

Live Preview

Pick a sample value, run $.type, and compare with typeof.

sample = null
$.type → "null"
typeof → "object"

jQuery Examples

Short, copy-ready snippets. Open DevTools Console, or use Try It Yourself for a live editor.

console.log($.type(undefined));  // "undefined"
console.log($.type(null));       // "null"
console.log($.type(true));       // "boolean"
console.log($.type(3));          // "number"
console.log($.type("test"));     // "string"
console.log($.type([]));         // "array"
console.log($.type({}));         // "object"

undefined
null
boolean
number
string
array
object

console.log(typeof null);   // "object"
console.log($.type(null));  // "null"

object
null

var list = ["a", "b", "c"];
var map = { 0: "a", 1: "b", length: 2 };

console.log($.type(list));  // "array"
console.log($.type(map));   // "object"

array
object

var when = new Date();
var pattern = /^\d+$/;

console.log($.type(when));     // "date"
console.log($.type(pattern));  // "regexp"
console.log(typeof when);      // "object"

date
regexp
object

Performance Notes

Type checks are cheap next to DOM work. Prefer the narrowest native test for your case instead of always asking for a full type string.

Key Takeaways