C/C++对char*字符串的操作

﹏ヽ暗。殇╰゛Y 2023-02-18 11:58 20阅读 0赞

## C/C++自写的字符串操作函数 ##

//连接字符串
    void Strcat(char *before, char *after);
    //复制字符串
    void Strcpy(char *newstr, const char *oldstr);
    //获取字符串长度
    size_t Getlenth(const char *str);
    //转化为小写
    void Strlwr(char *str);
    //转化为大写
    void Strupr(char *str);
    //比较字符串是否相等
    bool Strcmp(const char *str1, const char *str2);
    //将字符串2插入字符串2的指定位置
    void StrInsert(const char *str1, const char *str2, int point);

实现部分

#include <stdio.h>
    #include <stdlib.h>
    #include "teststring.hpp"
    void Strcat(char *before, char *after)
    { 
        while (*before != '\0')
        { 
            before++;
        }
    
        while (*after != '\0')
        { 
            *before = *after;
            before++;
            after++;
        }
        *before = '\0';
    }
    
    void Strcpy(char *newstr, const char *oldstr)
    { 
        while (*oldstr != '\0')
        { 
            *newstr = *oldstr;
            newstr++;
            oldstr++;
        }
        *newstr = '\0';
    }
    
    size_t Getlenth(const char *str)
    { 
        size_t length = 0;
        if (str != NULL)
        { 
            while (*str != '\0')
            { 
                length++;
                str++;
            }
        }
        return length;
    }
    
    //转化为小写
    void Strlwr(char *str)
    { 
        while (*str != '\0')
        { 
            if (*str <= 'Z' && *str >= 'A')
            { 
                *str -= 'A' - 'a';
            }
            str++;
        }
    }
    
    //转化为大写
    void Strupr(char *str)
    { 
        while (*str != '\0')
        { 
            if (*str <= 'z' && *str >= 'a')
            { 
                *str -= 'a' - 'A';
            }
            str++;
        }
    }
    
    //比较字符串是否相等
    bool Strcmp(const char *str1, const char *str2)
    { 
        if ((*str1 != '\0') && (*str2 != '\0'))
        { 
            return true;
        }
        while ((*str1 != '\0') && (*str2 != '\0'))
        { 
            if (*str1 - *str2 != 0)
            { 
                return false;
            }
        }
        return true;
    }
    
    //将字符串2插入字符串2的指定位置
    void StrInsert(char *str1, char *str2, int point)
    { 
        char *str1_buff = str1;
        size_t str1length = Getlenth(str1);
        size_t str2length = Getlenth(str2);
        char *tempstr = new char[str1length + str2length];
        char *tempstr_buff = tempstr;
        for (int i = 0; i < point; i++)
        { 
            *tempstr_buff = *str1_buff;
            tempstr_buff++;
            str1_buff++;
        }
        while (*str2 != '\0')
        { 
            *tempstr_buff = *str2;
            tempstr_buff++;
            str2++;
        }
        while (*str1_buff != '\0')
        { 
            *tempstr_buff = *str1_buff;
            tempstr_buff++;
            str1_buff++;
        }
        *tempstr_buff = '\0';
        Strcpy(str1, tempstr);
        delete tempstr;
    }