Constructors

[hamsterman]

hi
I have two questions:

1. How to use constructors when creating an array?
for example:

#include <iostream>
using namespace std;
struct OBJ{
    OBJ(int x){
        cout<<x;//do something
    }
}
int main{
    OBJ* o=new OBJ[20];//Where should I write the parameters
    return 0;
}

2. How to use constructors with struct/class members?
example:

struct ENT{
    OBJ x;//it's the same OBJ struct as above
    ENT(){
        //here I get this error:
        //'OBJ' : no appropriate default constructor available
    }
};

int main(){
    ENT e;
    return 0;
}

[Bazzy]

You should provide a constructor with no arguments or with only optional arguments.

[hamsterman]

Is there any other way?
I don't find constructors with no arguments very useful.

[zipuch]

2. How to use constructors with struct/class members?

struct ENT {
       OBJ x;
       ENT():x(4){
       }
};

[zipuch]

1. How to use constructors when creating an array?

//this not the right solution, but can be useful

#include <iostream>
using namespace std;

struct ENT{
    static int defult;
    OBJ x;
    ENT():x(defult){
    }
};

int main{
    OBJ::defult = 3;
    OBJ* o=new OBJ[20];
    return 0;
}

[jsmith]

To your first question there is no other way other than default constructor.