Thread: comparing two strings

Originally Posted by Soulzityr

it returns -1 if first is before, 1 if second is before, 0 if equal

By the way, please do not rely on this. Rely only on comparison for less than, equal to, and greater than 0.

Originally Posted by Soulzityr

The method is as follows:

Code:

strcmp(char String[], char String2[]);

it returns -1 if first is before, 1 if second is before, 0 if equal

you are right about 0... 1 and -1 are not guaranteed

strcmp() is not a "method" , it's a standard C function, have some respect.
Methods are for cool boarders, and .NET'ers.

Here are some ideas to kick around:

Code:

/*Yes , well a string is in a character array right?  eg: */
#include <stdio.h>

int main(void)
{
   int i;
  char s1[] = "Hello";      
  char s2[] = { 'H', 'e', 'l', 'l', 'o', '\0', '\0', '\0' };

/*
Strings defined in double quotes are automatically appended with the null character: '\0' (zero).
The string declarations above stored identically except that s2 will be two bytes larger.
Their "sizes" are  6 and 8 respectively but their string lengths are  both 5. 
*/

  printf("sizes: s1: %u    s2: %u  \n\n", sizeof(s1),  sizeof(s2) );

/*
We "index" (number) the string characters, like any array, starting with zero.
So you could make a loop and print the characters from index 0 until you run into the '\0':    
*/

  for ( i= 0; i < (int)sizeof(s2); i++ )
  {
    printf("s2[%d] = %c  %02x \n", i, s2[i], s2[i]); 
  } 
  putchar('\n');

/* We could also make a loop to print the same index of both s1 and s2: */

  for ( i= 0; ; i++ )
  {
    /* stop when the first \0 of either string is encountered */
    if ( s1[i] == '\0' || s2[i] == '\0' )
    {
      break;
    }
    printf("s1[%d] = %c  %02x  ,  s1[%d] = %c  %02x \n", 
                                          i, s1[i], s1[i], i, s2[i], s2[i] );
  } 

  printf("\nThe shorter string's length is: %d \n", i );

  printf("\nIt doesn't take too much imagination to see how the second loop \n\
could be used to compare two strings and calculate a meaningful value. \n\n\
...and from there taken to a function that returns a meaningful value! \n");

  return 0;
}
/*****  output :  ********************
sizes: s1: 6    s2: 8  

s2[0] = H  48 
s2[1] = e  65 
s2[2] = l  6c 
s2[3] = l  6c 
s2[4] = o  6f 
s2[5] =   00 
s2[6] =   00 
s2[7] =   00 

s1[0] = H  48  ,  s1[0] = H  48 
s1[1] = e  65  ,  s1[1] = e  65 
s1[2] = l  6c  ,  s1[2] = l  6c 
s1[3] = l  6c  ,  s1[3] = l  6c 
s1[4] = o  6f  ,  s1[4] = o  6f 

The shorter string's length is: 5 
***********************************/

Now try fooling around with the characters is s1 and s2....
And yes you should look up strcmp(). Here is a nice C reference: :The C Library Reference Guide
And NOWHERE in there are "methods" mentioned !!! whippersnappers!