@fav/arith.subtract

Calculates an accurate difference of two numbers.

"fav" is an abbreviation of "favorite" and also the acronym of "for all versions". This package is intended to support all Node.js versions and many browsers as possible. At least, this package supports Node.js >= v0.10 and major Web browsers: Chrome, Firefox, IE11, Edge, Vivaldi and Safari.

Install

To install from npm:

$ npm install --save @fav/arith.number @fav/arith.subtract

NOTE: npm < 2.7.0 does not support scoped package, but old version Node.js supports it. So when you use such older npm, you should download this package from github.com, and move it in node_modules/@fav/arith.subtract/ directory manually.

Usage

For Node.js:

var ArithNumber = require('@fav/arith.number');
var subtract = require('@fav/arith.subtract');

var num1 = ArithNumber.of(1.23);
// => { numerator: 123, denominator: 1, exponent: -2 }

var num2 = ArithNumber.of('4.56');
// => { numerator: 456, denominator: 1, exponent: -2 }

1.23 - 4.56;
// => -3.3299999999999996

var num3 = subtract(num1, num2);
// => { numerator: -333, denominator: 1, exponent: -2 }
num3.toApproximateString();
// => '-3.33'

var num4 = num1.subtract(num2);
// => { numerator: -333, denominator: 1, exponent: -2 }
num4.toApproximateString();
// => '-3.33'

For Web browsers:

<script src="fav.arith.number.min.js"></script>
<script>
var ArithNumber = fav.arith.number;

var num1 = ArithNumber.of(1.23);
// => { numerator: 123, denominator: 1, exponent: -2 }

var num2 = ArithNumber.of('4.56');
// => { numerator: 456, denominator: 1, exponent: -2 }

1.23 - 4.56;
// => -3.3299999999999996

var num3 = subtract(num1, num2);
// => { numerator: -333, denominator: 1, exponent: -2 }
num3.toApproximateString();
// => '-3.33'

var num4 = num1.subtract(num2);
// => { numerator: -333, denominator: 1, exponent: -2 }
num4.toApproximateString();
// => '-3.33'
</script>

API

subtract(arithNum1, arithNum2) : ArithNumber

Subtracts arithNum1 and arithNum2 and creates a new ArithNumber object which has the difference of these two numbers.

Parameters:

Parameter	Type	Description
arithNum1	ArithNumber	An ArithNumber object to be subtracted.
arithNum2	ArithNumber	An ArithNumber object to be subtracted.

Returns:

A new ArithNumber object having the difference of two numbers.

Type: ArithNumber

ArithNumber.prototype.subtract(num) : ArithNumber

This package attaches subtract function to ArithNumber's prototype as its method.

This method subtracts a parameter num of which is either a number, a string or an ArithNumber object from the value of this ArithNumber object itself, and returns a new ArithNumber object having this subtracted value.

Parameters:

Parameter	Type	Description
num	number | string | ArithNumber	A number, a string, or an ArithNumber to be subtracted.

Returns:

A new ArithNumber object having the difference of two numbers.

Type: ArithNumber

Checked

Node.js (4〜)

Platform	4	5	6	7	8	9	10
macOS	◯	◯	◯	◯	◯	◯	◯
Windows10	◯	◯	◯	◯	◯	◯	◯
Linux	◯	◯	◯	◯	◯	◯	◯

io.js (1〜3)

Platform	1	2	3
macOS	◯	◯	◯
Windows10	◯	◯	◯
Linux	◯	◯	◯

Node.js (〜0.12)

Platform	0.8	0.9	0.10	0.11	0.12
macOS	◯	◯	◯	◯	◯
Windows10	◯	◯	◯	◯	◯
Linux	◯	◯	◯	◯	◯

Web browsers

Platform	Chrome	Firefox	Vivaldi	Safari	Edge	IE11
macOS	◯	◯	◯	◯	--	--
Windows10	◯	◯	◯	--	◯	◯
Linux	◯	◯	◯	--	--	--

License

Copyright (C) 2018 Takayuki Sato

This program is free software under MIT License. See the file LICENSE in this distribution for more details.