Have you written a calculator?

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I tried to write one in C++ but failed. In whatever language you know have you wrote a calculator.

I did some math helping tools in flash, quite useful.

What sort of calculator? One of those ones with the buttons? I wrote a simple one of those once in Smalltalk.

Writing a calculator is a pretty standard exercise for those studying language parsers. I've put together one before.

I'm unclear about what we are talking about here. Are we talking about an expression evaluator that you give a string like say "3 * 2 + 5" and it comes back with a result, or are we talking about a "desktop" calculator that has buttons you can click?

I am a perplexed myself, MoonPatrol.

That type of calculator is what I mean.

I get it, interesting term to give it.

Are you interested in solving this problem from a pragmatic point of view (that is, "how do you write an arithmetic expression evaluator with the least amount of effort?"), or from a theoretical point of view ("how do these things work?").

From a pragmatic point of view in C++, you would find some library that someone has already written and just use that. Some other languages have a built-in evaluator that you could use.

From a theoretical point of view, we are getting into parsing, and things start to get complicated ...

Writing an RPN (reverse polish notation) calculator is pretty easy in most langugages... parsing is handled by employing a simple LIFO-type data structure like a stack.

There is even hardware that uses LPN, namely HP calculators.

Yes, and a classic way of evaluating normal ("infix") arithmetic expression is to convert them to RPN (or "postfix") first. There's an algorithm out there to do this.

I have written a calculator in PHP where you type in an expression and it solves it for you.

Once I tried writing a "button" calculator using html and javascript but it didn't work too well.

I created a calculator back in my high school CS1 days. By the way, you might want to change the topic to read: Have you "written" a calculator.

I was never into programming but I had a cousin that did that. It was kinda neat.

I once used BASIC to make a celsius farenheit converter...

So Farenheit 911 equals Celsius 450...

Bung!

911°F = 488°C

To convert Celsius to Fahrenheit: °F = 1.8 x °C + 32 | {9/5 = 1.80}

To convert Fahrenheit to Celsius: °C = °F - 32 x .555 | {5/9 = .555}


Here's how it's broken down: 1.8 x 488°C + 32 = 910.4°F, rounded to 911°F &
                                               911°F - 32 x .555 = 487.8°C, rounded to 488°C