C语言str几个常用方法总结

#include <stdio.h>

拷贝方法

char* strcpy(char* dest,char* src){

    char* ret = dest;

    /*

    while(*src != 0){

        *dest = *src;

        dest++;

        src++;

    }

    *dest = '\0';

    */

    while((*dest++) = (*src++));

    return ret;

}

拼接方法

char* strcat(char* dest,char* src){

    char* ret = dest;

    while(*dest != 0) dest++;

    while((*dest++) = (*src++));

    return ret;

}

求长度方法

int strle(char* str){

    int len;

    len = 0;

    while(*str != 0){

        str++;

        len++;

    }

    return len;

}

比价方法

int strcmp(char* dest,char* src){

    char* temp = dest;

    if(strle(dest) != strle(src)){

        return 0;

    }

    else{

        while(*dest != 0){

            if(*dest != *src){

                return 0;

            }

            dest++;

            src++;

        }

    }

    return 1;

}

int main()

{

    char y[] = "china";

    char x[] = "china";

    printf("%d\n",strcmp(y,x));

    return 0;

}

学习到的知识：

char y[] = "china"; 与char* y = "china"；两者区别

前者china是从常量区里复制到栈区的，所以我们是可以读写的

后者china是常量区的字符串，不可以对他进行写的操作