Question

我非常擅长编程，而且我正在学习C ++。我尝试使用矢量进行这项练习，但它们让我很困惑。我认为这段代码应该可行，但我不知道为什么我的IDE会说v未定义。

#include <iostream>
#include <string>
#include <vector>
using namespace std;

class check_input
{
public:
    void checkInput();
    void getnum();
    void displaynum();


private:
    vector<int> x;
    int sum = 0;
    int n = -1;

};

void check_input::checkInput()
{
    sum = 0;
    n = -1;

}

void check_input::getnum()
{
    int x;
    cout << "Please enter the number of values you want to sum, starting with the first: ";
    cin >> n;
    if (n < 1)
    {
        cout << "the number of elements must be a positive integer" << endl;
    }
    else
    {
        cout << "Please enter some integers (press '|' to stop): ";
        while (cin >> x) v.push_back(x);

        if (v.size() < n)
        {
            cout << "too few numbers; we need " << n << endl;
        }
        else
        {
            for (int i = 0; i < n; ++i) sum += v[i];
        }
    }
}


void check_input::displaynum()
{
    cout << "The sum of the first " << n << " numbers ( ";
    for (int i = 0; i < n; ++i) cout << v[i] << ' ';
    cout << ") is " << sum << '\n';
}

Answer 1

因为您没有定义该变量。

请尝试在正确范围中定义，并且不会出现IDE错误。：）

Answer 2

您没有定义向量v，将vector<int> v;添加到您的代码

为什么是标识符＆＃34; v＆＃34;未定义？

2 个答案: