为什么这行得通?使用 cin 读取小于给定输入的字符数组

I'm reading C++ Primer Plus (6th Edition) and I've come across some sample code in chapter 4 which I have a question about:

清单 4.2 strings.cpp

// strings.cpp -- storing strings in an array
#include <iostream>
#include <cstring> // for the strlen() function
int main()
{
    using namespace std;
    const int Size = 15;
    char name1[Size]; // empty array
    char name2[Size] = "C++owboy"; // initialized array
    // NOTE: some implementations may require the static keyword
    // to initialize the array name2
    cout << "Howdy! I'm " << name2;
    cout << "! What's your name?
";
    cin >> name1;
    cout << "Well, " << name1 << ", your name has ";
    cout << strlen(name1) << " letters and is stored
";
    cout << "in an array of " << sizeof(name1) << " bytes.
";
    cout << "Your initial is " << name1[0] << ".
";
    name2[3] = ''; // set to null character
    cout << "Here are the first 3 characters of my name: ";
    cout << name2 << endl;
    return 0;
}

代码本身不会引起任何混乱，但我一直在运行它，并且对某个场景感到困惑.

|H|o|w|C|a|n|I|P|o|s|s|i|b|l|y|F|i|t|T|h|i|s|E|n|t|i|r|e|S|t|r|i|n|g|I|n|?|...
^                             ^
|    These characters fit     |
         in the array