Number Type

Description

Number type is the reference type for numeric values.

To create a Number object, use the Number constructor and a number. Here's an example:

Conversion

Number type overrides valueOf() to return the primitive numeric value represented by the object.

It has toLocaleString(), and toString() to return the number as a string.

The toString() method optionally accepts a single argument indicating the radix.

var num = 10;
console.log(num.toString());       //"10"
console.log(num.toString(2));      //"1010"
console.log(num.toString(8));      //"12"
console.log(num.toString(10));     //"10"
console.log(num.toString(16));     //"a"
console.log(num.valueOf());/*  ww w . j  a  va2  s.  co m*/

The code above generates the following result.

Note

The typeof and instanceof operators work differently when dealing with primitive numbers versus reference numbers.

var numberObject = new Number(10);
var numberValue = 10;
console.log(typeof numberObject);   //"object"
console.log(typeof numberValue);    //"number"
console.log(numberObject instanceof Number);  //true
console.log(numberValue instanceof Number);   //false
/*  w w  w  .  j  ava2  s.c om*/

Primitive numbers always return "number" when typeof is called on them, whereas Number objects return "object". Similarly, a Number object is an instance of Number, but a primitive number is not.

The code above generates the following result.