An implementation prototype of strcmp in the C language

An implementation prototype of strcmp in the C language

Implementation code:

int  __cdecl  strcmp  (   
         const  char  *  src,   
         const  char  *  dst   
         )   
 {   
         int  ret  =  0  ;   
   
         while(  !  (ret  =  *(unsigned  char  *)src  -  *(unsigned  char  *)dst)  &&  *dst)   
                 ++src,  ++dst;   
   
         if  (  ret  <  0  )   
                 ret  =  -1  ;   
         else  if  (  ret  >  0  )   
                 ret  =  1  ;   
   
         return(  ret  );   
 } 

Function prototype: int strcmp(const char *dest, const char *source);

Return value: returns an integer value if dest > source, the return value is greater than 0, if dest = source, the return value is equal to 0, if dest < source, the return value is less than 0. Character sizes are arranged according to the dictionary sequence of characters.

Parameter description: all characters ending with ''/0"

Implementation;

int strcmp(const char *dest, const char *source) 
{ 
  assert((NULL != dest) && (NULL != source)); 
  while (*dest && *source && (*dest == *source)) 
      { 
          dest ++; 
          source ++; 
      } 
  return *dest - *source; 
/* if dest > source, The return value is greater than 0 If the dest = source, The return value is equal to 0 If the dest < source , The return value is less than 0 . */ 
} 

The above is an example of the prototype of strcmp in C language. If you have any questions, please leave a message or go to the community of this website for discussion. Thanks for reading.