如何匹配除指定字符和字符串之外的所有内容？ 正则表达式

Question

I am building a graph drawer and currently working on the math expression parser. I'm done with most parts but I'm stuck at clearing the input text before parsing it. What I'm trying to achieve now is getting rid of unpermitted characters.

For example, in this text:

5ax+4asxxv+sdflog10aloga(132*43)sin(132)

I want to match everything that is not + , - , * , / , ^ , ( , ) , ln , log , sin , cos , tan , cot , arcsin , arccos ,... and replace them with "" .

so that the output is

5x+4xx+log10log(132*43)sin(132)

I need help with the regex.

Spaces don't matter since I clear them out beforehand.

Answer 1

A little bit tricky - at least I couldn't think of a simple way to do what you ask. The regex would get monstrous.

So I did it the other way around - match what you want to keep, and put it back together.

The regex:

[\d+*/^()x-]|ln|log|(?:arc)?(?:sin|cos)|tan|cot

The code:

 var re = /[\\d+*/^()x-]|ln|log|(?:arc)?(?:sin|cos)|tan|cot/g, text = '5ax+4asxxv+sdflog10aloga(132*43)sin(132)arccos(1)'; console.log(text.match(re).join(''));