In Unity I'm trying to make it so you enter an expression and then it outputs a value but I want to use variables like:
x = 10
"x + x * 10"
^
outputs 200
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derHugo
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1I don't understand your "equation". – Elec1 Aug 06 '22 at 06:27
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That's an "expression" not an "equation" and you'd be "evaluating" not "solving" it. Do you have something that evaluates text _without_ variables (e.g. `"10 + 10 * 10"`)? – Lance U. Matthews Aug 06 '22 at 07:07
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Have a look at `DataTable` class `Compute` method: create `DataTable` instance, add *columns* with variable names - `x` in your case, add *row* with variable values - `10` in your case and `Compute` the formula - `x + x * 10` – Dmitry Bychenko Aug 06 '22 at 07:09
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1Why do you expect 200 as output value? I would expect 110. – Elec1 Aug 06 '22 at 09:56
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@Elec1 Evidently `+` has the same or greater precedence than `*`. – Lance U. Matthews Aug 06 '22 at 16:52
2 Answers
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You will need to create a Mathematical expression evaluator. This is essentially an algorithm to tokenize your input string and then evaluate every single token. Just search for "Mathematical expression evaluator in c# " and you'll find what you need.Because this is a quite large project on its own, it might make sense to use a library for that. Here are some libraries:
dragon
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If you feel more adventurous you could even write your own évaluator using a parser library. This will allow specific behaviors if needed. Some libraries are :
Olivier Duhart
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