基于范围的for循环

using namespace std;
int () {
    int a[] = {1, 2, 3, 4, 5};
    
    int n = sizeof(a) / sizeof(*a);		//元素个数
    //auto f = [] () {cout << sizeof(a) << endl;};
    for(int i = 0; i < n; ++i){
        cout << a[i] << ' ';
    }
    cout << endl;

    for(auto i : a){
        cout << i << ' ';
    }
    cout << endl;

    for(int i = 0; i < n; ++i){
        int &temp = a[i];
        temp = 2 * temp;
        cout << temp << ' ';
    }
    cout << endl;

    for(int &temp : a){
        temp = 2 * temp;
        cout << temp << ' ';
    }
    cout << endl;
    return 0;
}

using namespace std;

void func(int a[]){
    for(auto i : a){		//err，编译失败
        cout << i << ' ';
    }
    cout << endl;
    return;
}

int (){
    int a[] = {1, 2, 3, 4, 5};
    func(a);
    return 0;
}