CODEWITHSUNDEEP
c++function
user1279988
user1279988

Reputation: 763

function with parameter initialize

My question is based on effect of the sentence void print(const string& msg = ""), What difference if compared with void print(const string& msg),

When i use the print function in main(), could I call the function without passing a parameter for function print()? like p.print()?

class Point {
      int i, j, k;
    public:
      Point(): i(0), j(0), k(0) {}
      Point(int ii, int jj, int kk)
        : i(ii), j(jj), k(kk) {}
      void print(const string& msg = "") const {
        if(msg.size() != 0) cout << msg << endl;
        cout << "i = " << i << ", "
             << "j = " << j << ", "
             << "k = " << k << endl;
      }
    };

    int main() {
      Point p, q(1,2,3);
      p.print("value of p");
      q.print("value of q");
    } ///:~

Upvotes: 0

Views: 232

Answers (2)

Ozair Kafray
Ozair Kafray

Reputation: 13539

Yes, you can do that. it is known as a default value for a parameter. So, calling p.print() is the same as calling p.print("").

Default value to a parameter while passing by reference in C++ is also relevant reading for you.

Upvotes: 2

Luchian Grigore
Luchian Grigore

Reputation: 258618

Yup, that's a default parameter. If you don't supply one, an empty string will be used.

So, calling p.print() would be equivalent to calling p.print("").

Upvotes: 3

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