i need help on how to make a calculator program on C.

for example:
100+3*(344-45)-3/20= ?

ive done a part of it, but it doesnt even give the right answer. the user inputs anything (excluding letters and some puncts). it accepts the equation as a string. ive already converted the string into integers using atoi() fn but im stucked and i dont know what to do next. i made a program similar to this but it doesnt follow the precedence of the operators and it cant compute the answer when you include parenthesis on it...

*anything from telling me what to do next will do or any other will do* ill just try to analyze all your answers and see if i can really get it... :lol:

## All 3 Replies

Oddly enough, I answered this very question on another forum yesterday. The trick is to convert the expression to postfix so that you can easily evaluate it with a stack based approach. Alternatively, you could build an expression parse tree, but that just adds extra unnecessary steps in most cases.

Though I can't specifically say that you're doing a homework problem, the signs are there. We don't do work for you. Please post some code, and we'll help you troubleshoot.

i need help on how to make a calculator program on C.

for example:
100+3*(344-45)-3/20= ?

ive done a part of it, but it doesnt even give the right answer. the user inputs anything (excluding letters and some puncts). it accepts the equation as a string. ive already converted the string into integers using atoi() fn but im stucked and i dont know what to do next. i made a program similar to this but it doesnt follow the precedence of the operators and it cant compute the answer when you include parenthesis on it...

*anything from telling me what to do next will do or any other will do* ill just try to analyze all your answers and see if i can really get it... :lol:

did you already fix this????? i ned program like yours too.........

commented: Epic fail. -4