51 lines
1.8 KiB
Markdown
51 lines
1.8 KiB
Markdown
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# number-precision [](http://badge.fury.io/js/number-precision) [](https://travis-ci.org/nefe/number-precision) [](https://codecov.io/gh/nefe/number-precision)
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Perform addition, subtraction, multiplication and division operations precisely using javascript
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### Why
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```js
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0.1 + 0.2 = 0.30000000000000004
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1.0 - 0.9 = 0.09999999999999998
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0.105.toFixed(2) = 0.1 // not 0.11
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```
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### Install
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```
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npm install number-precision --save
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```
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### Methods
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```js
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NP.strip(num) // strip a number to nearest right number
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NP.plus(num1, num2, num3, ...) // addition, num + num2 + num3, two numbers is required at least.
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NP.minus(num1, num2, num3, ...) // subtraction, num1 - num2 - num3
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NP.times(num1, num2, num3, ...) // multiplication, num1 * num2 * num3
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NP.divide(num1, num2, num3, ...) // division, num1 / num2 / num3
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NP.round(num, ratio) // round a number based on ratio
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```
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### Usage
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```js
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import NP from 'number-precision'
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NP.strip(0.09999999999999998); // = 0.1
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NP.plus(0.1, 0.2); // = 0.3, not 0.30000000000000004
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NP.plus(2.3, 2.4); // = 4.7, not 4.699999999999999
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NP.minus(1.0, 0.9); // = 0.1, not 0.09999999999999998
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NP.times(3, 0.3); // = 0.9, not 0.8999999999999999
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NP.times(0.362, 100); // = 36.2, not 36.199999999999996
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NP.divide(1.21, 1.1); // = 1.1, not 1.0999999999999999
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NP.round(0.105, 2); // = 0.11, not 0.1
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```
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PS: If you want to get rid of `XXX is beyond boundary when transfer to integer, the results may not be accurate`, use this at the beginning of your app to turn off boundary checking.
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```js
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NP.enableBoundaryChecking(false); // default param is true
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```
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### License
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MIT
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