The Number JavaScript object is a wrapper object that lets us work with numbers by providing us with various constants and methods. A primitive number can be created by the Number() function. A JavaScript number is a double-precision 64-bit binary format IEEE 754 value.
We create a Number object using the Number function by writing the following code-
new Number('123'); const a = new Number('123'); const b = Number('123');
The main purpose of the Number function is to create a number from a string. The Number constructor used with the new operator is for creating a Number object, which is of type “object” instead of “number.” A number primitive isn’t an instance of Number. The data type for a primitive number value is a number. The type with the typeof operator and the constructor that it’s constructed from with the instanceof operator, are as in the following code -
console.log(typeof new Number('123')); console.log(new Number('123') instanceof Number);
We get “object” and true respectively when we run the two lines of code above. On the other hand, if we write this code instead -
console.log(typeof Number('123')); console.log(Number('123') instanceof Number);
By the help of Number() constructor, you can create number object in JavaScript. For example -
var n=new Number(value);
If value can't be converted to number, it returns NaN(Not a Number) that can be checked by isNaN() method. You can direct assign a number to a variable also. For example -
<!DOCTYPE html> <html> <body> <script> var x=103;//integer value var y=103.7;//floating point value var z=13e4;//exponent value, output: 130000 var n=new Number(18);//integer value by number object document.write(x+" "+y+" "+z+" "+n); </script> </body> </html>
Output
103 103.7 130000 18
The JavaScript Number Object is a reference for numeric values. A Number object is created using the Number constructor and then pass number as values. the method toString() is used to return the number as a string, the method accepts a single argument to denote the radix of the number.
Example
<!DOCTYPE HTML> <html> <head> <title>JavaScript Number Object: toString() Method </title> <style> body{font-family:Helvetica;} </style> <script> var mynumber = new Number(14); document.write("Convert <b>10</b> number to string : " + mynumber.toString()+ "<br>"); document.write("Convert <b>10</b> number to string(radix 2) : " +mynumber.toString(2)+ "<br>"); document.write("Convert <b>10</b> number to string(radix 8) : " +mynumber.toString(8)+ "<br>"); document.write("Convert <b>10</b> number to string(radix 10) : " +mynumber.toString(10)+ "<br>"); document.write("Convert <b>10</b> number to string(radix 16) : " +mynumber.toString(16)+ "<br>"); </script> </head> <body> </body> </html>
Output
Convert 10 number to string : 14 Convert 10 number to string(radix 2) : 1110 Convert 10 number to string(radix 8) : 16 Convert 10 number to string(radix 10) : 14 Convert 10 number to string(radix 16) : e
In Javascript number type include floating-point and integer values, its wrapper for primitive numeric values. A Number object is created using the Number() constructor. In Javascript numbers can be divided into two groups -
Integers
The numbers such as 120, -232, and 5.
floating-point
The fractional numbers such as 4.33, -8.422, and .55
In Javascript primitive number can be declared using the literal notation -
Syntax
<html> <head> <title>My first Javascript code</title> var x = 13.44; // A number with decimals var y = 45; // A number without decimals </head> <body> </body> </html>
OR, you can use Number global object directly
<html> <head> <title>My first Javascript code</title> var val = new Number(number); </head> <body> </body> </html>