cjaime

so i was given an assignment to make a calculator in c. i needed two call functions, one to get get information from the user, and one to do the next operation. the first function consist of a sole scanf statement and gets both the operator and right operand. the second function is a switch statement to do the next operation.
my problem is that the project stipulations state that the starting number must be zero, meaning the first input should consist of an opertor and operand. thus, the user would put +5 and the calculator should 0+5. the following operation should be, for example, input:+5 answer 10. for some reason i cant get it to do this. instead any input after the first try gives an answer of 0.
the reason i beleive there is a problem with the switch is that when i try to q (input q) i have to do it twice. the first time i put in q i get an answer of 0 and am returned to the program, in order to quit, i must enter q a second time.
i know this is probably more confusing than anything else, but i was wondering if there is a common problem with switch statements that would cause this. i wont put my code here because theres 90 lines of it, and im not sure what part you need to see.
i would appreciate any help.
thanks.

Polyphemus_

The only common problem with switches i know is that people often forget to terminate every case with a break:

Master

I think a switch is like a while loop. that why it require a break. it execute the block of code as long as the case is true.

Polyphemus_

Wrong. It doesn't stop executing code after a case with the right value, unless you break.

ivan

A switch it's more like many connected if-elseif constructs, but that's only me...

jim mcnamara

If you post your code, we don't have to guess about what might be wrong.

Polyphemus_

I believe it uses less stack than if-else if constructs.

bl00dninja

this sounds like basic administrative stuff. there are many possible causes for your problems, all minor logic errors or syntax errors. we need to see the code.

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nnxion

Mind that switch needs constant cases to work. OP, like others said: post the code.

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Berto

Erm you dont need a break in every statement in a switch, only if you want it to execute one section.

The way a switch statement works is by going down looks for the first case it meets then keep flowing down running all the code below it until it hits a break which will cause it to exit.

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