c++ fizzbuzz switch statement?

Question

I'm trying to see if I can make a fizzbuzz c++ switch statement. I'm getting an error saying i is not usable in a const expression. Does that mean I can't make this thing work? Or is there a work around? Here's my code.

#include <iostream>
using namespace std;

int main() {
    for(int = 1; 1 <= 100; i++){
        switch(true){

            case(i % 3 == 0 & i % 5 == 0):
                cout << "fizzbuzz" << endl;
                break;

            case(i % 3 == 0):
                cout << "fizz" << endl;
                break;

            case(i % 5 == 0):
                cout << "fizz" << endl;
                break;
            default:
                cout << i << endl;
        }
    }
}

Looks like you nee to revisit how `switch` works: http://en.cppreference.com/w/cpp/language/switch — NathanOliver, Aug 03 '17 at 17:32
You cannot use `switch` / `case` that way. Use `if` , `else if` instead. — user0042, Aug 03 '17 at 17:33
I think you need to read a good C++ book first. There's a lot of errors in this code — UnholySheep, Aug 03 '17 at 17:33
[List of good C++ books](http://stackoverflow.com/q/388242/253056). — Paul R, Aug 03 '17 at 17:33

Paul R · Accepted Answer · 2017-08-03T17:56:44.867

6

If you really want to use switch/case then you could do it like this:

switch (i % 15)
{
    case 0 : cout << "fizzbuzz\n"; break;

    case 5:
    case 10: cout << "buzz\n"; break;

    case 3:
    case 6:
    case 9:
    case 12: cout << "fizz\n"; break;

    default: cout << i << "\n"; break;;
}

edited Aug 03 '17 at 17:56

answered Aug 03 '17 at 17:37

Paul R

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Well, the `default` case, should, be `cout << i << endl;`, as is in the question. – Algirdas Preidžius Aug 03 '17 at 17:48
1

Thanks man, I get what i was doing wrong by what you showed. Interesting how it works, I appreciate it. – Daniel Archuleta Aug 04 '17 at 18:00

MrJLP · Answer 2 · 2017-08-03T17:42:51.963

There are a couple of fundamental problems with how you're using switch/case.

The expected way to use it is to have the switch refer to a variable or expression, then the case sections refer to constant values.

Instead what you're doing is switch(true) which doesn't make any sense, even though it compiles. It's equivalent to switch(1). So in that case only case 1: would ever apply.

You cannot use expressions for case. These must be constant integer values. So for example you can either plain integers case 0:, or also commonly pre-processor defines case FIZZBUZZ:.

score 0 · Answer 3 · answered Aug 03 '17 at 17:40

0

As stated in the comments, several times, you cannot always use a switch() statement like a if statement and there are several other issues with your code. I am not going to give you the right answer as I don't believe that will help you the most.

Here are some notes:
1) Instead of a switch you should use if, else if, and else statements.
2) In C++ a and is expressed as && not &
3) A for loop is declared like for(int i = 0; i <= 100; i++)

You should watch/read some simple tutorials on how to code C++ as it is important you understand these basics.

answered Aug 03 '17 at 17:40

Error - Syntactical Remorse

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I know how to with an if else statement, was just trying to get creative – Daniel Archuleta Aug 05 '17 at 01:20
@DanielArchuleta Use what works best for what you are trying to do. A switch isn't creative if you are "trying" to use it. – Error - Syntactical Remorse Aug 05 '17 at 01:22
All I'm trying to see was if it was possible to use a switch statement, for fun you know, i'm not using it for anything. – Daniel Archuleta Aug 05 '17 at 03:05

c++ fizzbuzz switch statement?

3 Answers3