为什么不能使用“="运算符将数组变量直接分配给另一个数组变量? [英] Why can't I assign an array variable directly to another array variable with the '=' operator?

问题描述

为什么下面的赋值不起作用?如果可能的话，我想要一个低级的解释.另外，这是我得到的编译器错误:'char*' 到 'char [20]' 的赋值中的类型不兼容

Why does the following assignment not work? I would like a low-level explanation if possible. Also, here's the compiler error I get: incompatible types in assignment of 'char*' to 'char [20]'

class UCSDStudent {

  char name[20];

  public:

    UCSDStudent( char name[] ) {
      //this-> name = name; does not work! Please explain why not
      strcopy( this -> copy, copy ); //works 
    }

};

推荐答案

因为当你有这样的函数调用时 UCSDStudent( char name[] ) 只有数组的地址 name 被复制而不是整个数组.这是一个 C\C++ 特性.

Because when you have a function call like this UCSDStudent( char name[] ) only the adress of the array name is copied instead of the whole array. It is a C\C++ feature.

此外，定义为 char name [20] 的 name 不是可修改的左值.

Furthermore the name defined as char name [20] is not a modifiable lvalue.

关于 strcpy:它会带来未定义的行为，就好像您的源数组没有 NULL 字符一样，它也会将一些垃圾复制到 this->name.您可以在此处

Regarding strcpy: it will bring undefined behaivour as if your source array doesn't have a NULL character it will copy some trash to this->name too. You may read more about strcpy here

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