class Foo {
private:
    int myInt;
};

int Foo::myInt = 1;

class Foo {
private:
    int myInt;
public:
    Foo() : myInt(1) {}
};

class Foo {
private:
    static const int myInt = 1;
};

class Foo {
private:
  static int myInt;
};

class Foo
{
public:
    Foo(void) :
    myInt(1) // directly construct myInt with 1.
    {
    }

    // works but not preferred:
    /*
    Foo(void)
    {
        myInt = 1; // not preferred because myInt is default constructed then assigned
                   // but with POD types this makes little difference. for consistency
                   // however, it's best to put it in the initializer list, as above
                   // Edit, from comment: Also, for const variables and references,
                   // they must be directly constructed with a valid value, so they
                   // must be put in the initializer list.
    }
    */

private:
    int myInt;
};