1 
template<class T>
class Stack 
{
public:
    Stack()
    {
        cout<<"Enter size\n";
        cin>>size;
        //stackPtr=new int[size];
        stackPtr= new T[size];
        top =0;
    }

    ~Stack()
    {
        delete[] stackPtr;
    }

    void display()
    {
        cout<<"*****************************\n";
        for(int i=0;i<top;i++)
            cout<<stackPtr[i]<<endl;
        cout<<"*****************************\n";
    }

    bool Push()
    {
        int a;
        cout<<"Enter element\n";
        cin>>a;
        if(isFull()==false)
        {
            stackPtr[top++]=a;
            return true;
        }
        else
            return false;
    }

    bool Pop()
    {
        if(isEmpty()==false)
        {   
            top--;
            return true;
        }
        else 
            return false;
    }

    bool isEmpty()
    {
        if(top==0)
            return true;
        else
            return false;
    }

    bool isFull()
    {
        if(top==size)
            return true;
        else
            return false;
    }

private:
    //int *stackPtr;
    T *stackPtr;
    int size;
    int top;
    //location of the last element added, -1 means empty stack
};



void main()
{

    int typeArray;
    cout<<"What type of array do you want\n1.Integer\n2.Character\n";
    cin>>typeArray;
    //If instead of these if statements, i simply
        //write Stack<int> Stacks, everything works fine
        //So i think theres something wrong with using char or float or ANY other 
        //datatype?

    if(typeArray==1)
        Stack <int>Stacks;
    else 
        Stack <float>Stacks;

    cout<<"1.PUsh\n2.Pop\n3.Display all\n4.exit\n";
    int ch=1;
    cin>>ch;
    while(ch!=-1)
    {

        switch(ch)
        {
        case 1: if(Stacks.Push())
            {
                cout<<"Stack Full\nPop to enter other        values\n";

            }
            break;
        case 2: if(Stacks.Pop()==false)
                    cout<<"Stack EMpty\n";
            break;
        case 3: Stacks.display();
            break;
        case 4: exit(0);
        default:cout<<"Reenter you option\n";
            break;
        }
        cout<<"1.PUsh\n2.Pop\n3.Display all\n4.exit\n";
        cin>>ch;
    }
}

这些是我得到的错误。我正在使用 VS 2010

test.cpp(104): error C2065: 'Stacks' : undeclared identifier
test.cpp(104): error C2228: left of '.Push' must have class/struct/union type
                            is ''unknown-type''
test.cpp(110): error C2065: 'Stacks' : undeclared identifier 
test.cpp(110): error C2228: left of '.Pop' must have class/struct/union type
                            is ''unknown-type''
test.cpp(113): error C2065: 'Stacks' : undeclared identifier
test.cpp(113): error C2228: left of '.display'  must have class/struct/union type
                            is ''unknown-type''
4

1 回答 1

6 
if(typeArray==1)
    Stack <int>Stacks;
else 
    Stack <float>Stacks;

此代码段创建的变量Stacks的生命周期和范围仅限于if语句。它对程序的其余部分不可见。

你需要重新思考你的设计。

另外，我在这里看到一个逻辑错误：

bool Push()
{
    int a;
    cout<<"Enter element\n";
    cin>>a;

那不应该T代替int吗？这样，int无论模板专业化如何，您都只会阅读 s 。

于 2012-06-26T08:46:27.463 回答