基于char * 设计一个字符串类MyString，并且具有构造函数、析构函数、复制构造函数，重载运算符“+”，“=”， “+=”， “[]“，尽可能完善它，使之能满足各种需要。

迷南。 2022-12-02 03:51 19阅读 0赞

**基于char \* 设计一个字符串类MyString，并且具有构造函数、析构函数、复制构造函数，重载运算符“+”，“=”， “+=”， “\[\]"，尽可能完善它，使之能满足各种需要。**

#include <iostream>
    #include <cstring>
    using namespace std;
    class MyString { 
    private:
    	char* p;
    	int len;
    public:
    	MyString();
    	MyString(int n);
    	MyString(const char* temp);
    	MyString(const MyString& a);
    	~MyString();
    	char& operator[](int n);
    	MyString& operator=(const MyString& a);
    	MyString operator+(const MyString& a);
    	MyString& operator+= (const MyString & a);
    	void GetLen() {  cout << "Len: " << len <<  endl; }
    	void ShowString() { 
    		int i = 0;
    		while (p[i]) { 
    			cout << p[i];
    			i++;
    		}
    		cout << endl;
    	}
    };
    MyString::MyString() { 
    	p = new char[1];
    	p[0] = '\0';
    	len = 0;
    }
    MyString::MyString(int n) { 
    	len = n;
    	p = new char[n+1];
    	for (int i = 0; i <= n; i++)
    		p[i] = '\0';
    }
    MyString::MyString(const char* temp) { 
    	int i;
    	len = strlen(temp);
    	p = new char[len + 1];
    	for (i = 0; i < len; i++) { 
    		p[i] = temp[i];
    	}
    	p[i] = '\0';
    }
    MyString::MyString(const MyString& a) { 
    	len = a.len;
    	int i;
    	p = new char[len + 1];
    	for (i = 0; i < len; i++) { 
    		p[i] = a.p[i];
    	}
    	p[i] = '\0';
    }
    MyString::~MyString() { 
    	delete [] p;
    	len = 0;
    }
    char& MyString::operator[](int n) { 
    
    		return p[n];
    }
    MyString& MyString::operator=(const MyString& a) { 
    	delete[] p;
    	len = a.len;
    	p = new char[len + 1];
    	int i;
    	for (i = 0; i < len; i++) { 
    		p[i] = a.p[i];
    	}
    	p[i] = '\0';
    	return *this;
    }
    MyString MyString::operator+(const MyString& a) { 
    	int total = len + a.len;
    	MyString temp(total);
    	int i;
    	for (i = 0; i < len; i++)
    		temp[i] = p[i];
    	for (int j = 0; j < a.len; i++, j++)
    		temp[i] = a.p[j];
    	temp[i] = '\0';
    
    	return temp;
    }
    MyString& MyString::operator+= (const MyString& a) { 
    	int total = len + a.len;
    	MyString temp(total);
    	int i;
    	for (i = 0; i < len; i++)
    		temp[i] = p[i];
    	for (int j = 0; j < a.len; i++, j++)
    		temp[i] = a.p[j];
    	temp[i] = '\0';
    	*this = temp;
    	return *this;
    }
    int main() { 
    	MyString str1("Hello");
    	cout << "str1:" << endl;
    	str1.GetLen();
    	str1.ShowString();
    	MyString str2("World");
    	cout << "str2:" << endl;
    	str2.GetLen();
    	str2.ShowString();
    	MyString str3;
    	cout << "str3 = st31 + str2 :" << endl;
    	str3 = str1 + str2;
    	str3.GetLen();
    	str3.ShowString();
    	MyString str4;
    	cout << "str4 = str3" << endl;
    	str4 = str3;
    	str4.GetLen();
    	str4.ShowString();
    
    	return 0;
    }