关于c++的一个简单问题

Question

c++刚学，学长看一下我这代码为什么没输出？

#include<bits/stdc++.h>
using namespace std;

class counter
{
public:
    counter(int number);
    void increment();
    void decrement();
    int getvalue();
    int print();
private:
    int value;
};

counter::counter(int number)
{
    value = number;
}
void counter::increment()
{
    value++;
}
void counter::decrement()
{
    value--;
}
int counter::getvalue()
{
    return value;
}
int counter::print()
{
    cout << "Value is " << value << endl;
    return 0;
}

int main()
{
    counter (4);
    counter increment();
    counter decrement();
    counter getvalue();
    counter print();
    return 0;
}

Answer 1

 counter c(4);
    c.increment();
    c.decrement();
    c.getvalue();
    c.print();