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记一次学习范围for的时候碰到的for循环内加注释的蜜汁bug

作者:互联网

问题代码:

#include <bits/stdc++.h>
#include <vector>
using namespace std;
int main()
{
    //string 要引用
    string s = "hello";
    for (auto &i : s)    //书上说i 是char类型,那s[n]呢?
        i = toupper(i); //改变成大写,不影响s的值
    // cout << s << endl;    //s的值是 hello

    //array
    int arr[5] = {1, 2, 3, 4, 5};
    for (auto i : arr)
        //cout << arr[i] << endl;

    int a[] = {1, 2, 3, 5, 2, 0};
    vector<int> counts(a, a + 6);
    for (auto count : counts)
        cout << count << " ";
    cout << endl;
}

只跑后面的就能跑:

#include <bits/stdc++.h>
#include <vector>
using namespace std;
int main()
{

    int a[] = {1, 2, 3, 5, 2, 0};
    vector<int> counts(a, a + 6);
    for (auto count : counts)
        cout << count << " ";
    cout << endl;
}

百思不得其解,最后终于发现是注释的问题:

向for循环加括号就可以跑

去掉注释也可以跑:

#include <bits/stdc++.h>
#include <vector>
using namespace std;
int main()
{
    //string 要引用
    string s = "hello";
    for (auto &i : s)    //书上说i 是char类型,那s[n]呢?
        i = toupper(i); //改变成大写,不影响s的值
    // cout << s << endl;    //s的值是 hello

    //array
    int arr[5] = {1, 2, 3, 4, 5};
    for (auto i : arr)
    {
        //cout << arr[i] << endl;
    }
        

    int a[] = {1, 2, 3, 5, 2, 0};
    vector<int> counts(a, a + 6);
    for (auto count : counts)
        cout << count << " ";
    cout << endl;
}

所以问题是!!!注释

for循环中只有一行代码并且不加大括号并且带打上注释,!!!报错!!!

怀疑是编译器把int a[]这一行也识别成注释了

标签:cout,int,auto,内加,注释,蜜汁,counts,include,bug
来源: https://www.cnblogs.com/XUYICHENMO/p/15820023.html