What syntax should i use for member initializers?

Question

What syntax should i use for member initializers in c++?

I know how to use it for Attribute but not for functions.

#include <iostream>
using namespace std;

class MyClass {
    public:
        MyClass(int a, int b,int c):
            regVar(a), constVar(b),function(c)
        {}    
    public:
        int regVar;
        const int constVar;
        void function(int a){
            cout << a;
        }    
};
int main(){
    MyClass myclass(10,20);
    cout << myclass.regVar;
}

Thanks in advance

I tried function(c), c.function etc.