错误：没有匹配功能可调用&#39;Stack <int> ：：窥视（）&#39;

Question

I keep getting the following error: error: no matching function for call to 'Stack::Peek()'

I am new to C++ and I cannot figure out why I am getting the error

This is my Peek() function.

int Peek(T data)
{
    if(IsEmpty ())
        return -1;
     else
        return top -> data;

}

and this is my main() function.

int main()
{
    Stack<int> s1;

    cout << "*declare stack s1\ns1=" << s1 << endl; // stack initially set to 0
    cout << "s1.Size()=" << s1.Size() << endl;
    cout << "s1.IsEmpty()=" << ((s1.IsEmpty()) ? "T" : "F") << endl;
    cout << "s1.IsFull()=" << ((s1.IsFull()) ? "T" : "F") << endl;
    cout << "s1.Peek()=" << s1.Peek() << endl;
    cout << endl;

    Stack<char> s4;

    for (char c='a'; c<='z'; c++)s4.Push(c);
    cout << "s4=" << s4 << endl;
    cout << "s4.Size()=" << s4.Size() << endl;
    cout << "s4.IsEmpty()=" << ((s4.IsEmpty()) ? "T" : "F") << endl;
    cout << "s4.IsFull()=" << ((s4.IsFull()) ? "T" : "F") << endl;
    cout << "s4.Peek()=" << s4.Peek() << endl;
}

I get the error whenever the Peek function is called in main so I was wondering if anyone could help me with this.

Answer 1

You defined a Peek method, but not Stack::Peek. Your method should have this signature: int Stack::Peek(T data)

Answer 2

Because you are calling it without any argument. Your declaration:

int Peek(T data)

Your invocation:

s4.Peek()

Indeed a stack data type doesn't need an argument to the peek function (nor you use it). You should modify your original function to int Peek() .

Answer 3

Your function Peak is declared as having one parameter

int Peek(T data);

However you call it without any argument

cout << "s1.Peek()=" << s1.Peek() << endl;

So the compiler does not know a function with name Peak that has no parameter.