safe-math-js

Safer floating-point math operations in JavaScript that return results we expect, so that 0.1 + 0.2 adds up to 0.3, e.g., instead of 0.30000000000000004. Customized and fixed from package '@dfkaye/safe-math'.

Fixings from package @dfkaye/safe-math

• 0.0003 * 100000000 = 20000 (error), (fixed result = 30000)
• 0.00000003 * 100000000 = 300000000 (error), (fixed result = 3)

Some Existing Issue of @dip1059/safe-math-js

• 0.00000003 * 1000000000000000000 = 30000000000.000004 (error), should return 30000000000. For this kind of big integer(1000000000000000000) and large decimal value(0.00000003 equivalent to 3e-8) operations, wrap the output with Math.round() or parseInt(). e.g:

let result = safe-math-js.multiply(0.00000003, 1000000000000000000);
console.log(Math.round(result)); //30000000000

// or

result = safe-math-js.multiply(3e-8, 1000000000000000000);
console.log(parseInt(result)); //30000000000

Warning: you need to check the actual output then you have to decide whether to keep the result as it is or to wrap with round() or parseInt()

Basic Usage

const math = require('@dip1059/safe-math-js');

console.log(math.add(0.1, 0.2));
console.log(math.minus(0.1, 0.2));
console.log(math.divide(0.1, 0.2));
console.log(math.multiply(0.1, 0.2));

For more usage check the tests

Documentation

See full details at https://dfkaye.com/posts/2020/08/17/safer-math-operations-in-javascript-using-tdd/.

Install

npm install @dip1059/safe-math-js

OR

yarn add @dip1059/safe-math-js