C++ strncpy 意外输出

Question

我正在审查函数 strncpy 的字符串操作函数。我有 7 个输出而不是 3 个，谁能解释一下？非常感谢。

    char x[] = "just see that.";
    char y[15];
    char z[10];
    char l[14];

    strcpy(y, x);

    cout << "The string in array x is: " << x
         << "\n The string in array y is: " << y << '\n';

    strncpy(z, x, 9);
    z[9] = '\n';

    cout << "The string in array z is: " << z << endl;

    strncpy(l, x, 13);
    l[13] = '\n';

    cout << "The string in array l is: " << l<< endl;

输出有7行，如下图

The string in array x is: just see that.
The string in array y is: just see that.
The string in array z is: just see
just see that.
The string in array l is: just see that
just see
just see that.

Answer 1

如果你想空终止，你应该使用'\0'而不是'\n'