Numbers.md

JavaScript Numbers: Integer, Float, Binary, Exponential, Hexadecimal, Octal

The Number is a primitive data type used for positive or negative integer, float, binary, octal, hexadecimal, and exponential values in JavaScript.

The Number type in JavaScript is double - precision 64 bit binary format like double in C# and Java.It follows the international IEEE 754 standard.

The first character in a number type must be an integer value, and it must not be enclosed in quotation marks.The following example shows the variables having different types of numbers in JavaScript.

var num1 = 100; // integer
var num2 = -100; //negative integer

var num3 = 10.52; // float
var num4 = -10.52; //negative float

var num5 = 0xfff; // hexadecimal
var num6 = 256e-5; // exponential
var num7 = 030; // octal
var num8 = 0b0010001; // binary

Number() Function in JavaScript

The Number() is a constructor function in JavaScript that converts values of other types to numbers.

var i = Number('100');
var f = Number('10.5');
var b = Number('0b100');
typeof (i); // returns number
typeof (f); // returns number
typeof (b); // returns number

By using the new operator with the Number() function will return an object which contains constants and methods for working with numbers.

var i = new Number('100');
var f = new Number('10.5');
var b = new Number('0b100');
typeof (i); // returns object
typeof (f); // returns object
typeof (b); // returns object

Compare Numbers

Be careful while comparing numbers using == or === operators.The == operator compares object references and not the values whereas the === operator compare values.The following example compares numbers created by different ways.

var num1 = new Number(100);
var num2 = Number('100');
var num3 = 100;

num1 == num2; // true 
num1 === num2; // false

num2 == num3;//true
num2 === num3; // true

num1 == num3;//true
num1 === num3;//false

Number Properties

The Number type includes some default properties.JavaScript treats primitive values as objects, so all the properties and methods are applicable to both literal numbers and number objects.

Number.MAX_VALUE; //1.7976931348623157e+308  
Number.MIN_VALUE; //5e-324 
Number.NEGATIVE_INFINITY; //-Infinity 
Number.POSITIVE_INFINITY; //Infinity 
Number.NaN; //NaN 

Number Methods

Method	Description
toExponential(fractionDigits)	Returns exponential value as a string.
toFixed(fractionDigits)	Returns string of decimal value of a number based on specified fractionDigits.
toLocaleString()	Returns a number as a string value according to a browser's locale settings.
toPrecision(precisionNumber)	Returns number as a string with specified total digits.
toString()	Returns the string representation of the number value.
valueOf()	Returns the value of Number object.