What does this constructor imply??

Question

class A{
public:
A(int i=3):i(++i){}
void pri(){cout<<this->i;}

the above code has an constructor declared and a colon followed by it with some expressions what do they exactly imply?

Answer 1

They are called member initializers. All it does is initialize the specified member variables to the value contained within the parentheses

Answer 2

thanx @alex

can u say why it has 2 paranthesis?