我无法为动态 cstring 赋值并修改它们

Question

对于作业问题，我需要实现一个 cstring 类和重载运算符。但是，我在初始化 char 数组时遇到了麻烦。在下面的代码中，

StringClass::StringClass()
{
    c = new char[10];
    c = "Default";
    stringlength = strlen(c);
}

#pragma once
#include <fstream>
class StringClass
{
private:
    char* c;
    int stringlength;
public:
    StringClass();
    ~StringClass();
    void print()const;
    StringClass(char*, int);
    StringClass(const StringClass*);
    StringClass& operator=(const StringClass*);
    friend std::istream& operator>>(std::istream&, StringClass*);
    friend std::ostream& operator<<(std::ostream&, const StringClass*);
    StringClass& operator+(const StringClass*);
    char operator[](int);
};

对于行 c = "Default"; 我收到一个错误 const char* cannot be assigned to char*，但我没有将 c 设置为 const。如果我将 charc 更改为 const char c，我可以在构造函数中将其设置为默认值，但我无法进一步修改它。这是为什么呢？

编辑：我可以将声明更改为此并且它可以正常工作。这是正确的做法吗？

c = new char[10]{ "Default" };

完整的实现文件，

#include "StringClass.h"
#include <fstream>
#include <iostream>

StringClass::StringClass()
{
    c = new char[10];
    c = "Default";
    stringlength = strlen(c);
}

StringClass::~StringClass()
{
    c = NULL;
    delete c;
}

void StringClass::print()const
{
    for (int i = 0; i < 10; ++i)
        std::cout << c[i];

    std::cout<< std::endl;

    std::cout << stringlength;
}
StringClass::StringClass(const StringClass* p)
{
    for (int i = 0; i < 10; ++i)
    {
        c[i] = p->c[i];
    }
    stringlength = p->stringlength;
}

StringClass& StringClass::operator=(const StringClass* a)
{
    if (this == a)
        return *this;
    else
    {
        for(int i = 0; i < 10; ++i)
        c = &a->c[i];
        stringlength = a->stringlength;
    }
    return *this;
}

//std::istream& operator>>(std::istream& in, StringClass* a)
//{
    //in >> a->c >> a->stringlength;
    //return in;
//}

std::ostream& operator<<(std::ostream& out, const StringClass* a)
{
    out << a->c << " " << a->stringlength << std::endl;
    return out;
}

StringClass& StringClass::operator+(const StringClass* a)
{
    StringClass temp;
    temp.c = c + *a->c;
    temp.stringlength = stringlength + a->stringlength;
    return temp;
}

char StringClass::operator[](int a)
{
    return c[a];
}

Answer 1

c = new char[10]{ "Hello" };