How to detect last element within a map iterator

Question

I want to be able to detect the last iteration within my map iterator. How would I achieve this?

class JSON {
public:
    static void stringify(map<string, string> data)
    {
        string base;

        base += "{ ";

        for (map<string, string>::iterator it = data.begin(); it != data.end(); ++it)
        {
            cout << it->first.c_str() << " => " << it->second.c_str() << endl;
        }
    }
};

Answer 1

您可以像这样使用std :: prev：

    for(auto it = data.begin(); it != data.end(); ++it)
    {
        if(it == std::prev(data.end()))
        {
            // this is the last iteration
        }

        std::cout << it->first << " => " << it->second << '\n';
    }

std :: prev从其参数返回上一个迭代器。