C/C++中memcpy与strcpy之间的区别

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strcpy用于字符串间的拷贝,memcpy用于内存间的拷贝

strcpy的原型:char * strcpy(char *dest,const char *src);

              实现代码:

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

                         while((*dest++=*src++)!='\0');

                         return dest;

            }

memcpy的原型:void *memcpy(void *dest,const void *src,size_t n);

               实现代码:

           void *memcpy(void *dest,const void *src,size_t n){

                        char *pdest=(static_cast<char *>)dest;

                        const char *psrc=(static_cast<const char *>)src;

                        if(pdest>psrc&&pdest<psrc+n){                   //同一字段间的拷贝

                                     for(size_t i=n-1;i>=0;i--)pdest[i]=psrc[i];

                         }

                          else{

                                      for(size_t i=0;i<n;i++)pdest[i]=psrc[i];

                          }

                         return pdest;

                }

 

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