Memcpy() function copies two-dimensional array & memcmp() function compares two-dimensional array

ps: The header files of both functions are #include <string.h>

memcpy( ) function

memcpy( ) yes C/C++ Memory copy function used , The function prototype is void *memcpy(void *destin, void *source, unsigned n); The function copies several bytes from the starting position of the source memory address to the target memory address , namely From source source Middle copy n Bytes to target destin in .

#include <stdio.h>
#include <string.h>

int main( )
{
    
	
    int src[2][3] = {
     {
    1,2,3},{
    4,5,6}};
    int des[2][3] = {
     0 };
    
    // Put two-dimensional array src Copied to the des Array  
    memcpy(des, src, sizeof(src));
   	
   	// Print 
	for(int i = 0;i < 2;i++)
	{
    
		for(int j = 0;j < 3;j++)
		{
    
			printf("%d",des[i][j]);
		}
		printf("\n");
	}
	
    return 0;
}

memcmp( ) function

memcmp The prototype of the function is int memcmp(const void *str1, const void *str2, size_t n)); Its function is Store str1 And storage str2 Before n Compare bytes . Because it is based on memory byte comparison , Therefore, the actual data type to be compared can be integer 、 String, etc. .

#include <stdio.h>
#include <string.h>

int main( )
{
    
    int src[2][3] = {
     {
    1,2,3},{
    4,5,6}};
    int des[2][3] = {
     {
    1,2,3},{
    4,5,6}};
     
    int res = memcmp(des, src, sizeof(src));
    
   	printf("%d",res);
    
    return 0;
}

memcmp( ) The return value of the function is 0 Indicates that two arrays are the same , The return value is 1 Express des > src, The return value is -1 Express des < src