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65 lines
1.4 KiB
Markdown
65 lines
1.4 KiB
Markdown
<!-- Note: This file is automatically generated from source code comments. Changes made in this file will be overridden. -->
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# Function parser
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Create a parser. The function creates a new `math.expression.Parser` object.
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## Syntax
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```js
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math.parser()
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```
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### Parameters
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Parameter | Type | Description
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--------- | ---- | -----------
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### Returns
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Type | Description
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---- | -----------
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Parser | Parser
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## Examples
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```js
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const parser = new math.parser()
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// evaluate expressions
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const a = parser.eval('sqrt(3^2 + 4^2)') // 5
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const b = parser.eval('sqrt(-4)') // 2i
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const c = parser.eval('2 inch in cm') // 5.08 cm
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const d = parser.eval('cos(45 deg)') // 0.7071067811865476
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// define variables and functions
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parser.eval('x = 7 / 2') // 3.5
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parser.eval('x + 3') // 6.5
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parser.eval('function f(x, y) = x^y') // f(x, y)
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parser.eval('f(2, 3)') // 8
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// get and set variables and functions
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const x = parser.get('x') // 7
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const f = parser.get('f') // function
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const g = f(3, 2) // 9
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parser.set('h', 500)
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const i = parser.eval('h / 2') // 250
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parser.set('hello', function (name) {
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return 'hello, ' + name + '!'
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})
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parser.eval('hello("user")') // "hello, user!"
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// clear defined functions and variables
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parser.clear()
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```
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## See also
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[eval](eval.md),
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[compile](compile.md),
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[parse](parse.md)
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