【c语言】不用库函数自己实现字符串的复制

// 字符串的复制#include <stdio.h>//用数组下标实现char * my_strcpy( char *dst,char *src){int i = 0;while( *src != '\0'){dst[i++] = *src;src++;}dst[i] = '\0';return dst;}int main(){char dst[] = "bvfhrhljdhfleahf";char *src = "dandanwa";my_strcpy( dst,src);printf("复制后的字符串是：%s\n",dst);return 0;}//用指针实现#include <stdio.h>char * my_strcpy( char *dst,char *src){char *ret = dst;while( *src != '\0'){*dst = *src;src++;dst++;}*dst = '\0';return ret;}int main(){char dst[] = "bvfhrhljdhfleahf";char *src = "dandanwa";my_strcpy( dst,src);printf("复制后的字符串是：%s\n",dst);return 0;}//用指针实现，可以把功能函数里边的语句再进行优化缩减#include <stdio.h>char * my_strcpy( char *dst,char *src){char *ret = dst;while( *src != '\0'){*dst++ = *src++;}*dst = '\0';return ret;}int main(){char dst[] = "bvfhrhljdhfleahf";char *src = "dandanwa";my_strcpy( dst,src);printf("复制后的字符串是：%s\n",dst);return 0;}//当然也可以把语句写在循环条件里，更简洁#include <stdio.h>char * my_strcpy( char *dst,char *src){char *ret = dst;while( *dst++ = *src++){;}*dst = '\0';return ret;}int main(){char dst[] = "bvfhrhljdhfleahf";char *src = "dandanwa";my_strcpy( dst,src);printf("复制后的字符串是：%s\n",dst);return 0;}//为了让程序员调试起来更方便，可以加断言//哪个量不可以改变的时候记得给前边加const#include <stdio.h>#include <assert.h>char * my_strcpy( char *dst,char const *src){char *ret = dst;assert( ( dst != NULL ) && ( src != NULL ) );while( *dst++ = *src++){;}*dst = '\0';return ret;}int main(){char dst[] = "bvfhrhljdhfleahf";char *src = "dandanwa";my_strcpy( dst,src);printf("复制后的字符串是：%s\n",dst);return 0;}

，我们摇摇头说，困难其实没什么大不了。