Constructor and Variable Declaration in Cpp

Question

#include<bits/stdc++.h>
using namespace std;

class A{
    int x;

public:
    A(){
        x=10;
    }

    void show(){
        cout<<x<<endl;
    }
};

main(){

    A a;
    a.show();

}

In the main() function when I am declaring the variable a in the above way, the code works fine but if we declare the variable A a() compiler gives error. Why is it so? I think there is no problem regarding argument type matching. Can anyone help?

score 1 · Accepted Answer · answered May 02 '16 at 15:42

1

Because A a() is not a variable declaration but a function prototype declaration.

answered May 02 '16 at 15:42

MikeCAT

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score 0 · Answer 2 · answered May 02 '16 at 15:43

0

C++11 and above fix this problem with universal initializers. You are declaring a function that returns an A. If you instead use {} it will work:

A a{};

answered May 02 '16 at 15:43

Edward Strange

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Constructor and Variable Declaration in Cpp

2 Answers2