#include <iostream>
 
    class Foo {
    public:
        int m_i;  // member variable, m_xxx
        Foo(int); // constructor taking an int.
    };
 
    static int s_i;
 
    Foo::Foo(int i_)   // arguments use _ suffix
    {
        int i = i_;    // local value of i
        i *= 3;
        m_i = i;       // we're assigning it the local value, not the argument.
    }
 
    int main()
    {
        int i = 1;
        Foo foo(2);
        s_i = 3;
 
        std::cout << "i = "<<i<<", foo.m_i = "<<foo.m_i<<", s_i = "<<s_i<< std::endl;
    }
 

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