C library functions -memcmp()

C Standard Library - <string.h>

Description

C Library Functionsint memcmp(const void *str1, const void *str2, size_t n))Compare the storage areastr1and the storage areastr2the frontnCompare bytes.

Declaration

Below is the declaration of the memcmp() function.

int memcmp(const void *str1, const void *str2, size_t n)

Parameter

  • str1-- Pointer to a block of memory.
  • str2-- Pointer to a block of memory.
  • n-- Number of bytes to be compared.

Return Value

  • If the return value is < 0, it indicates that str1 is less than str2.
  • If the return value is > 0, it indicates that str1 is greater than str2.
  • If the return value is = 0, it indicates that str1 is equal to str2.

Example

The following example demonstrates the usage of the memcmp() function.

Example

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

int main ()
{
   char str1[15];
   char str2[15];
   int ret;

   memcpy(str1, "abcdef", 6);
   memcpy(str2, "ABCDEF", 6);

   ret = memcmp(str1, str2, 5);

   if(ret > 0)
   {
      printf("str2 is less than str1");
   }
   else if(ret < 0)
   {
      printf("str1 is less than str2");
   }
   else
   {
      printf("str1 is equal to str2");
   }
   
   return(0);
}

Let us compile and run the above program, which will produce the following result:

str2 小于 str1

C Standard Library - <string.h>

other extensions