Question

我似乎很难让这个加法运算符重载为我的对象工作。我已经在网上搜索过，并且无法弄清楚我做错了什么。基本上它应该重载以连接2个char数组。我尝试的所有内容都会导致崩溃或随机混乱的角色。

我是操作员重载的新手，所以也许我错误地使用了它。它叫：

String myString1, myString2; 
std:: cout << "\nYour strings added are: " << myString1 + myString2;

并在头文件中......

 String operator+(String);

以下是相关代码：

String String::operator+(String rhs){
String result;
int i = length;

for(int x = 0; x < length; x++)
{
        result.ch[x] = ch[x];
        std::cout << result.ch[x];
}

std:: cout << " ";

for (int j = 0; rhs.ch[j] != '\0'; ++i, ++j)
{
         result.ch[i] = rhs.ch[j];
         std::cout <<result.ch[i];
}

return result;
}

如果需要，我会提供完整的源代码。其他一切都很完美。

.HPP：

#include<iostream>
#include<string>

using std::istream;
using std::ostream;

const int default_size = 256;
class String
{

  public:

         // constructors
         String();
         String(const char ch, const int default_size);
         String(const String& rhs, int cap = default_size); // copy constructor

         // accessor functions
         void getLength(String str);
         void outPut(String str); 
         void findChar(String str);
         // destructor
         ~String (); // destructor

         // mutator functions
         void getInput(String str); 

         // friend I/O function overloads
         friend std::istream& operator>>(std::istream&, const String& str);
         friend std::ostream& operator<<(std::ostream&, const String& str);

         // operator overloads
         String operator+(String str);

  private:
          int strLength, length;
          int capacity;
          char ch[default_size];
          char *s; };

和.cpp

// String.cpp

#include "String.hpp"
#include<iostream>

// default constructor
String::String() 
{
}

// char constructor
String::String(const char ch, const int default_size)
{
capacity = default_size;
s = new char[capacity];
s[0] = ch;
s[1] = '\0';
strLength = 1;
}

//copy constructor
String::String(const String& rhs, const int cap)
{
// Check if string capacity is shorter than length
if (cap <= rhs.strLength)
    capacity = rhs.strLength + 1;
    else
        capacity = cap;

    s = new char[capacity];

// Copy chars to string
for (length = 0; rhs.s[length] != '\0'; ++length)
{
    s[length] = rhs.s[length];
}

s[length] = '\0';
}
// destructor
String::~String()
{
strLength = 0;
delete [] s;
}

// overloaded io operatiors
// Outputs string with << operator
ostream& operator<<(ostream& out, const String& str)
{
out << str.s;
return out;
}

// Inputs string with >> operator
istream& operator>>(istream& in, const String& str)
{
in >> str.s;
return in;
}

// gets users input
void String::getInput(String str)
{

 std:: cout << "Please enter a string.\n";
 std:: cin.getline(ch, default_size);

}

// getLength
void String:: getLength(String str)
{
  size_t strLength = strlen(str.ch);
  length = strLength;
  std:: cout << "The length is " << strLength << ".\n";
}

// output
void String:: outPut(String str)
{
 std:: cout << "\nYou entered.\n";
 for(int x = 0; x < str.length; x++)
 {
         std:: cout << ch[x];
 }
         std:: cout << "\n";
 }

// user enters a character, this provides the location(s)
void String:: findChar(String str)
{
char * charSearch;
char s;
std:: cout << "\nPlease enter a character to search for. \n";
std:: cin >> s;
std:: cout << "\n";
charSearch = strchr(ch, s);

while(charSearch != '\0')
{
                 std:: cout << "Found at: " << charSearch-ch+1 << "\n" ;
                 charSearch = strchr(charSearch+1, s);
}
std::cin.ignore();
}

// OPERATOR OVERLOADS---------------------------------------------------

// Addition operator 
// adds the right hand object to the lefthand object
String String::operator+(String rhs)
{
String result; 
int i = length;
for(int x = 0; x < length; x++)
{
        result.ch[x] = ch[x];
        std::cout << result.ch[x];
}

std:: cout << " ";

for (int j = 0; rhs.ch[j] != '\0'; ++i, ++j)
{
         result.ch[i] = rhs.ch[j];
         std::cout <<result.ch[i];
}
std::cout << "\nHere is result.ch: ";
for(int z = 0; result.ch[z] != '\0'; z++)
{
        std::cout << result.ch[z];
}

return result;
}

Answer 1

你遇到的问题多于连接问题，我怀疑其他所有事情都能很好地完成＃34;。

您的默认构造函数不会初始化任何内容即使String s; std::cout << s;也不起作用，String s; std::cin >> s;也不应该。{/ p>
您没有转让操作员 {String s1; String s2; s2 = s1;}很可能会崩溃。
您既有指针s又有数组ch 您将数据存储在s中，但有些代码使用ch代替你需要下定决心。
（并且不要像对成员那样使用与参数和局部变量相同的名称。）
您同时拥有strLength和length，并且随机使用它们。

您的代码中有更多未定义的行为，而不是任何人可能不愿意列出你最好的道路可能是抛弃代码并重新开始。

尝试通过operator +重载在不同的对象中添加2个char数组

1 个答案: