JavaScript | Numbers - GeeksforGeeks

JavaScript numbers are always stored as double-precision 64-bit binary format IEEE 754.

This format stores numbers in 64 bits,

0-51 bit stores value(fraction)
52-62 bit stores exponent
63 bit stores sign

The types of number literals You can use decimal, binary, octal, and hexadecimal.

Decimal Numbers:
JavaScript Numbers does not have different types of numbers(ex: int, float, long, short) which other programming languages do. It has only one type of number and it can hold both with or without decimal values.

Var a=33;
var b=3.3;
var x = 0562   //x will be 370(parsed as an octal number).

If the number starts with 0 and the following number is smaller than 8. It will be parsed as an Octal Number.

Integers are accurate up to 15 digits:

var a = 999999999999999;   // a will be 999999999999999
var b = 9999999999999999;     // b will be 10000000000000000

Floating point is not 100% accurate. The maximum number of decimals is up to 17.

var x = 0.22 + 0.12;   //x will be 0.33999999999999997

Example-1:

<!DOCTYPE html> 
<html> 
  
<body> 
  
    <h2> 
      JavaScript Numbers 
  </h2> 
  
    <p id="num"></p> 
  
    <script> 
        var x = 0.22 + 0.12; 
        document.getElementById( 
          "num").innerHTML =  
          "0.22 + 0.12 = " + x; 
    </script> 
  
</body> 
  
</html> 

Output:

Binary Numbers
They starts with 0b or 0B followed by 0’s and 1’s.

var x = 0b11;        // x will be 3
var x = 0B0111;       // x will be 7

Example-2:

<!DOCTYPE html> 
<html> 
  
<body> 
  
    <h2> 
      JavaScript Numbers 
  </h2> 
  
    <p id="num"></p> 
  
    <script> 
        var x = 0 B0111; 
        document.getElementById( 
          "num").innerHTML =  
          "0B0111 will be " + x; 
    </script> 
  
</body> 
  
</html> 

Output:

Octal Numbers
They start with 0 followed by a number ranges from 0-7.if any number is used it will be taken as a decimal number.

var x = 0111;      //x will be 73
var x = 07123;     //x will be 3667

Example-3:

<!DOCTYPE html> 
<html> 
  
<body> 
  
    <h2> 
      JavaScript Numbers 
  </h2> 
  
    <p id="num"></p> 
  
    <script> 
        var x = 07123; 
        document.getElementById( 
          "num").innerHTML =  
          "07123 will be " + x; 
    </script> 
  
</body> 
  
</html> 

Output:

Hexadecimal Numbers
They start with 0x or 0X followed by any digit belonging (0123456789ABCDEF)

var x = 0xfff;         //x will be 4095

Example-2:

<!DOCTYPE html> 
<html> 
  
<body> 
  
    <h2>JavaScript Numbers</h2> 
  
    <p id="num"></p> 
  
    <script> 
        var x = 0xfff; 
        document.getElementById( 
          "num").innerHTML =  
          "0xfff will be " + x; 
    </script> 
  
</body> 
  
</html> 

Output:

Exponentiation:

var x = 2E5   // x will be 200000
var x = 34e3   // x will be 34000
var x = 23e-5 //x will be 0.00023

JavaScript uses the + operator for both addition and concatenation.

Additon:

var a = 20;
var b = 20;
var c = a + b;           // c will be 40 (a number)

Concatenation:

var a = "10";
var b = "20";
var c = a + b;           // c will be 2020 (a string)

Numeric Strings
NaN is a reserved word indicating not a number.

 var x= "12345" ;        // x will be a string(NaN)   
 var x = 67 ;            // x will be number

My Personal Notes

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