CODEWITHSUNDEEP
c++return
minecraftplayer1234
minecraftplayer1234

Reputation: 2227

Return with "?:" operator

So I have to do a simple program for my college class, which would include a structure fraction with numerator and denominator as ints and a function is_correct() checking two conditions: is denominator!=0 and is nominator<denominator. If two of them are true, then I should return true, otherwise false. I'm obligated to use ?: operator. So here's my code:

struct fraction {int n,d;
                bool is_correct(){
                    d!=0?(return n<d?true:false):return false;
                };
                };

I mean, I guess I could use one if with condition d!=0, but I have to use only ?:, and g++ gives me that: expected primary-expression before 'return'

Upvotes: 2

Views: 112

Answers (3)

nhgrif
nhgrif

Reputation: 62052

If two of them are true, then I should return true, otherwise false

This is a pretty standard truth table, right?

   | T | F
---+---+---
 T | T | F
---+---+---
 F | F | F

And I know an operator that has an identical truth table: &&.

We don't need a ternary here at all. We can simply write:

return d != 0 && n < d;

An even more concise solution looks like this:

return d && n<d;

But I'll make the case that the first solution more clearly expresses the coder's intent, which is an important consideration.

Upvotes: 5

mustafagonul
mustafagonul

Reputation: 1209

struct fraction {
  int n,d;

  bool is_correct() {
    return d != 0 ? (n < d ? true : false) : false;
  };
};

Upvotes: 1

Drew McGowen
Drew McGowen

Reputation: 11706

Just move the return outside of the condition (spacing added for clarity):

return d != 0 ? (n < d ? true : false) : false;

Upvotes: 3

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