Three non-standard types of numbers in JavaScript and two libraries

JavaScript has one type of number by default - Number. Although it is of course divided into Int and Float, although it is expressed in a little (for example, in the parseInt functions - parseFloat).
In this case, large numbers (both Int and Float) are shortened, and fractions are reduced to decimal and rounded. Both are not always good, so libraries have appeared that offer new classes for unusual numbers.

BigInt

Numbers (both Int and Float) are shortened to 15 characters. In Int, the remaining digits are stored as zeros. Example:

>> 100000000000000000111
  100000000000000000000

The library is called BigNumber , numbers need to be transferred in the form of a line. We use:

var num = new BigNumber('100000000000000000001');
num.add(1); // 100000000000000000002

The rest on the library page , there are most of the necessary functions (+ - * /), accept numbers, strings, and the same BigNumber.

Bigfloat

There is also a Float, there are also 15 characters there, but the extra digits are simply thrown away.

>> 3.14159265358979323
  3.141592653589793

You can use the same library in the same format:

var pi = new BigNumber('3.14159265358979323');
pi.add('0.00000000000000003'); // 3.14159265358979326

Fraction

The third type is fractions. The number is rounded. And because of this, the result may go bad.

>> 1/3
  0.3333333333333333
>> 1/3 + 2/3
  1
>> 0.3333333333333333 + 0.6666666666666666
  1

And we have the library Fraction.js .

var a = new Fraction(1,3);
a.add( new Fraction(2,3) ); // 1

That's all

Thanks for attention