参数化字符串类设计-优快云博客

本文介绍了一个参数化的字符串类的设计与实现，该类能够处理不同类型的字符数据，并提供了多种常用字符串操作方法，如连接、比较等。

Create a parametric string type. The basic type is to act as container class that contains a class T object. In the prototype case, the object is a char. The normal end-of-string sentinel is 0. The standard behavior should model the functions found in the string library. The class definition could parameterize the sentinel as well. Such a type exists in the standard library string.

创建一个参数化字符串类型，它是一个包含对象class T的容器类。在字符串原型中，对象是char类型，字符串结束标志是0。实现该参数化类型时可模仿string库，类定义时也可以将字符串结束标志进行参数化。

//本程序用VCSP6编译通过

#include<iostream>
#include<cassert>
#include<string>
using namespace std;

const int max_size = 100;

template<typename T>
class my_string
{
public:
     my_string(const my_string& str)//define constructor
{
  len = str.len;
  end = str.end;
  for(int i = 0; i < len; i++)
  {
   s[i] = str.s[i];
  }
}; // constructor function 1

my_string()
{
  len = 0;
  end = 0;
  s[0] = end;
};

my_string(const T * str,const T End):end(End)
{
  len = 0;
  while(str[len] != end)
  {
   s[len] = str[len++];
  }
  s[len] = end;
} ; // constructor function 2

~my_string() {} ; // destructor function

my_string& operator=(const my_string& str) // '=' -> overloading,assignment operations
{
  len = str.len;
  end = str.end;

  for(int i = 0; i < len; i++)
  {
   s[i] = str.s[i];
  }

  return *this;
};

T operator[](int index) // overloading of '[]'
{
  return s[index];
};

//define the friend functions
friend my_string& operator+(const my_string& str1,const my_string& str2); //the overloading of '+'

friend bool operator==(const my_string& str1,const my_string& str2); // judge if two strings are equal

int size()
{
  return len;
};

bool empty()
{
  return len == 0;
};

void print()
{
   for(int i=0;i<len;i++)
    cout<<s[i];

cout<<endl;

};

private:
int len; //record the length of the string
T end; //the ends of a string
T s[max_size]; // s stores the string
};

template <typename T>
bool operator==(const my_string<T>& str1,const my_string<T>& str2)
{
if(str1.len == str2.len)
{
  for(int i = 0; i < len; i++)
  {
   if(str1.s[i] != str2.s[i])
    return 0;
  }
  return 1;
}
return 0;
}

template <typename T>
my_string<T> operator+(const my_string<T>& str1,const my_string<T>& str2) //the overloading of '+'
{
my_string newmy_string;
newmy_string.len = str1.len + str2.len - 1;

for(int i = 0; i < str1.len; i++)
{
newmy_string.s[i] = str1.s[i];
}

for(int j = 0; j <= str2.len; j++)
{
newmy_string.s[i+j] = str2.s[j];
}

return newmy_string;
}

int main()
{
    char a;
int a1;
double a2;
char type1[10];
int type;
    char up[100];
int flag1=0,flag2=0,flag3=0;
int number1[100], num;
double number2[100];

cout << "我实现了 +,==,=,[] ,empty(),size()这六个功能,欢迎使用" << endl;
cout<<"********************************************************"<<endl;
cout<<"请输入您需要的类型(char int or double):"<<endl;
cin>>type1;
if(strcmp(type1,"char")==0)
  flag1=1;
if(strcmp(type1,"int")==0)
  flag2=1;
if(strcmp(type1,"double")==0)
  flag3=1;
cout<<"请输入结束标志:(对应您输入的类型)"<<endl;
if(flag1==1)
  cin>>a;
if(flag2==1)
  cin>>a1;
if(flag3==1)
  cin>>a2;
cout<<"*******************************************************"<<endl;

cout<<"请输入数据:"<<endl;
cout<<"如果您选择char 型，输入一行数据，以对应结束标志结束"<<endl;
cout<<"如果是其他类型，请输入数的个数"<<endl;
if(flag1==1)
{
   cin>>up;

}
if(flag2==1)
{

   cin>>num;
   for (int i = 0; i < num; i++)
   {
    cout << "请输入第" << i+1 << "个数" << endl;
    cin >> number1[i];
   }
   number1[num] = a1;

}
if(flag3==1)
{
   cin>>num;
   for(int i=0;i<num;i++)
   {
    cout << "请输入第" << i+1 << "个数" << endl;
    cin >> number2[i];
   }
   number2[num]=a2;
}
my_string<char> temp1(up, a);
my_string<int> temp2(number1, a1);
my_string<double> temp3(number2, a2);
cout<<"****************************************************"<<endl;
cout<<"1.打印整行数据:"<<endl;
cout<<"2.求输入数据量的大小:"<<endl;
cout<<"0.结束操作:"<<endl;
cin>>type;
while(type!=0)
{
   switch(type)
   {case 1:

   {
    if(flag1==1)
    temp1.print();

    if(flag2==1)
    temp2.print();

    if(flag3==1)
    temp3.print();
   }
   break;
   case 2:
    {
     if(flag1==1)
      cout<<temp1.size()<<endl;
     if(flag2==1)
      cout<<temp2.size()<<endl;
     if(flag3==1)
      cout<<temp3.size()<<endl;
    }
    break;