Conversion of CharSequence to maths expression

Question

In my App i have two TextViews one contains an expression eg. 3 + 4 =

And the second contains an answer eg. 7

How would i go about turning this into a valid maths expression so the app could calculate it and return the answer as an int?

Answer 1

Depending on the complexity of the expressions you expect in your TextViews, you might need to construct a parser/interpreter for them. If that's the case, I heartily recommend ANTLR . For more information about using ANTLR on Android, see this question .

Another parser generator that I know of is JavaCC , but ANTLR is a lot more flexible and powerful.