分析现有字符串处理的功能,建立一个能够对字符串进行处理的类 MyString。要求写出成员函数的功能,并实现之。
分析:
定义MyString类,实现一些字符串处理功能,
具体实现,成员有char*字符串,其它函数基本上都是将c语言字符串处理函数进行一些封装
具体代码:
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#include "stdafx.h" #include <iostream> using namespace std; class MyString { public: MyString() { pStr = NULL; } MyString(char* str) { pStr = new char[strlen(str) + 1]; strcpy(pStr, str); } ~MyString() { if (pStr) { delete[] pStr; pStr = NULL; } } void operator=(char* str) { if (pStr) { delete[] pStr; pStr = NULL; } pStr = new char[strlen(str) + 1]; strcpy(pStr, str); } void operator+=(char* str) { int oldLen = length(); int len = oldLen + strlen(str) + 1; char* pStrTemp = new char[len]; for (int i = 0; i < oldLen; i++) { pStrTemp[i] = pStr[i]; } for (int i = oldLen; i < len; i++) { pStrTemp[i] = str[i- oldLen]; } if (pStr) { delete[] pStr; pStr = NULL; } pStr = pStrTemp; } void clear() { if (pStr) { delete[] pStr; pStr = NULL; } } void assign(char* str) { if (pStr) { delete[] pStr; pStr = NULL; } pStr = new char[strlen(str) + 1]; strcpy(pStr, str); } int length() { return strlen(pStr); } char* c_str() { return pStr; } private: char* pStr; }; int main() { MyString str("mystring"); cout << str.c_str() << endl; str = "赋值重载="; cout << str.c_str() << endl; str.assign("赋值函数"); cout << str.c_str() << endl; str += "重载+=操作符"; cout << str.c_str() << endl; cout << str.length() << endl; system("pause"); return 0; } |
运行结果: