distinguish between number and letters in an Edit text

Question

I want the user to tap on an Edit text operations, such as 1+3-5 then he/she press for long to get the result? my issue is that how can I let the app differentiates between numbers and operations(+,-,*)?

I am trying to create a simple calculator, the user should enter 3+7+5 then long press and the app should presents the result on the EditText. — Alnfiai, Mar 27 '16 at 03:20
you should use the regular expression I'm trying a method to do what you want. — humazed, Mar 27 '16 at 03:29

score 0 · Answer 1 · edited May 23 '17 at 12:07

0

you can use code like this.

    ScriptEngineManager mgr = new ScriptEngineManager();
    ScriptEngine engine = mgr.getEngineByName("JavaScript");
    String foo = "(40+2)*10";
    try {
        System.out.println(engine.eval(foo));
    } catch (ScriptException e) {
        e.printStackTrace();
    }

but be aware that this method doesn't follow the presence of mathematical operations.

but this library or that do.

for further reading take a look at this question.

edited May 23 '17 at 12:07

Community

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answered Mar 27 '16 at 04:06

humazed

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thanks a lot. I will try them on and post again the final outcome. – Alnfiai Mar 27 '16 at 14:19

distinguish between number and letters in an Edit text

1 Answers1