c ++ object initialization (Weng Kai c ++ class disclosed [10])

c ++ object initialization is to call the constructor initialization operation is completed;

Constructor Constructor whether the parameters, there are parameters constructor, the default constructor (compiler give us achieve) ... (said after the copy constructor)

Note: The default constructor only if we ourselves do not declare the constructor will gave us a no argument constructor compiler, if we define, the compiler will not have control

Example: see below the class C compiler does not give us a default constructor to initialize

#include <the iostream> 

class A    // default constructor A () which is at compile time, the compiler to achieve our 
{
};

class B
{
public:
    B () {}       // no argument constructor 
};

class C
{
public:
    C ( int I) {}   // have argument constructor 
};

class D
{
public:
    D () {}   // no constructor parameter 
    D ( int I) {}   // have argument constructor 
};

int main ()
{
    A a;
    B b;
    C C;    // error only in the case where no constructor will give us a compiler manufacturing default constructor with no arguments 
    C C1 ( . 1 );   // OK 
    D D, D1 ( 0 );    // OK 
    return  0 ;
}

 An error saying: Can not find the constructor C :: C () to initialize the object c