how to split positive and negative numbers?

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i want to type the numbers in a textbox:
1+24+32-4+2-12
and then display the result.
so how can i split the positive numbers and the negatives?
or is there any other way to do it ?

Posted 19-Feb-13 10:48am

appleduardo

Updated 19-Feb-13 10:59am

v2

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Richard C Bishop 19-Feb-13 16:51pm

You can use the .Split() that returns an array and then do what you want with them.

Sergey Alexandrovich Kryukov 19-Feb-13 17:10pm

I suggested a pretty unusual but quite practical solution, please see...
—SA

Maciej Los 19-Feb-13 16:53pm

I think, you mean "operators" ("+", "-")...

Sergey Alexandrovich Kryukov 19-Feb-13 17:09pm

I have that very funny solution I just promised. It's quite reasonable, depending on the purpose of all that, at least much more interesting than the boring parsing...
—SA

Zoltán Zörgő 19-Feb-13 17:00pm

Note, that this is an expression, there are no negative numbers, only substraction operators.

Sergey Alexandrovich Kryukov 19-Feb-13 17:10pm

I suggested a pretty unusual but quite practical solution, please see...
—SA

Sergey Alexandrovich Kryukov 19-Feb-13 17:01pm

First of all, why parsing such thing? And what's the problem; what did you try so far?
—SA

Jibesh 19-Feb-13 17:10pm

it may be possible but if you can tell whats the need of such thing we can able to provide you a better way of doing it.

Sergey Alexandrovich Kryukov 19-Feb-13 17:14pm

I have that very funny solution I just promised. It's quite reasonable, depending on the purpose of all that, at least much more interesting than the boring parsing...
—SA

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Sergey Alexandrovich Kryukov · Answer 1 · 2013-02-19T11:08:00

Solution 2

Of course you can parse, interpret it, and show the result. But this is kind of boring.

I can advise one "exotic" alternative: wrap the input in C# code, compile it using CodeDOM, execute (you will have to use a separate Application Domain, to avoid memory leak! see below), and show the result, if it was successful, otherwise show compilation error.

Please see my past answers:
code generating using CodeDom[^],
Create WPF Application that uses Reloadable Plugins...[^].

Not a very simple solution, but you can do a lot more with that.

If something is not quite clear, I'll gladly explain. It works.

—SA

Posted 19-Feb-13 11:08am

Sergey Alexandrovich Kryukov

Updated 19-Feb-13 11:11am

v2

Comments

Maciej Los 19-Feb-13 17:14pm

This is not funny answer, but full professional answer! 5^5!

Sergey Alexandrovich Kryukov 19-Feb-13 17:19pm

Nor "full" neither "professional" is a barrier for being funny. :-)
Thank you, Maciej.
—SA

appleduardo 19-Feb-13 18:19pm

would you help me to do it by the "boring" way ? please! i dont understand much the way you said is a good way 2do it.

Sergey Alexandrovich Kryukov 19-Feb-13 18:31pm

I say, boring... :-)

Help with what? Just use logic. This is just work, no secrets to share. Don't use string.Split, loop by all charters, have 3 "modes": digits, blank spaces, sign, invalid (for other characters; throw exception when you face them). This way, split. Remove blank spaces why splitting, just don't add them to the list. Find numeric values using, say uint.Parse. Do not consider negative values, treat '-' as operators, not a part of the number. Summarize taking sign into consideration. Simple, boring... The biggest thing: this is one-time work. Should you add operators, brackets, and you will need to do it all again.
OK, I described the solution, but I should have asked: what did you try so far?..

Better use my approach.

—SA

**Zoltán Zörgő** · Answer 2 · 2013-02-19T11:08:00

You better use or write an expression evaluator.
You can use the classical approach as described here: Building Expression Evaluator with Expression Trees in C# – Improving the API[^]
Use a third party library as this one: http://csharpeval.codeplex.com/[^]
Or use the reflection to emit code: http://www.daniweb.com/software-development/csharp/code/351471/simple-math-expression-evaluator-using-emit[^]
Or use CodeDom to run dynamic code at runtime, like described here: http://devreminder.wordpress.com/net/net-framework-fundamentals/c-dynamic-math-expression-evaluation/[^]