Pointers and cstring length

问题

I am setting pointers here one to point to name and one to point to name again but get the lenth. How come when i use cout << strlen(tail); it keeps telling me the lenth is 3? Even if i enter something that is 12?

#include <iostream>
#include <stdio.h>
#include <string.h>
using namespace std;

int main()
{
    char name[0];
    cout << "Please enter your name: ";
    cin.getline(name, 256);
    cout << "Your name: " << name << endl;

    char* head = name;
    cout << head[6] << endl;

    char* tail = name;
    cout << strlen(tail);

    return 0;
}

回答1:

With

char name[0];

You are allocating a buffer of size 0 in which to store data. You need to make it big enough for the longest string you will enter (plus 1 for the NUL terminator), which would be 256 in this case (because you're reading 255 characters and a NUL with cin.get(name, 256)):

char name[256];

回答2:

Name is declared as zero length. That is going to be a problem.

来源：https://stackoverflow.com/questions/8539763/pointers-and-cstring-length