javascript 将等式字符串转换为等式
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Convert equation string to equation
提问by maxhud
Possible Duplicate:
Running an equation with Javascript from a text field
How can I convert the following:
我如何转换以下内容：
var n = "2x^3+3x+6";
To
到
var x = a number
var n = 2x^3+3x+6;
In JavaScript?
在 JavaScript 中？
回答by tjdecke
Quite hard to guess what the exact requirements and the context are, but if you want to roughly stick to the grammar demonstrated by your variable I'd suggest using a math expression parser.
很难猜测确切的要求和上下文是什么，但是如果您想粗略地坚持您的变量所展示的语法，我建议您使用数学表达式解析器。
Using js-Expression-eval, it could look like this:
使用js-Expression-eval，它可能如下所示：
var formula = "2*x^3+3*x+6";
var expression = Parser.parse(formula);
var result = expression.evaluate({ x: 3 });
Run the Fiddle
运行小提琴
Should you want to have your own grammar - to leave out the * symbols for multiplication with variables, for example - you'll have to roll your own parser, for example using something like jison.
如果您想拥有自己的语法 - 例如，省略用于与变量相乘的 * 符号 - 您必须推出自己的解析器，例如使用jison 之类的东西。
回答by Micha?l Benjamin Saerens
var x = a number;
var n = eval("2*Math.pow(x,3)+3*x+6")
