Thread: evaulate strcmp true/false

In C, 'true' is any non-0 integer value, and 'false' is 0.

It might help to try something like this...

Code:

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

// Untested
int main (void)
{
 char name[20];
 printf ("Boolean expression program\n");

 printf ("Gimme a word less than 20 chars long.\n");
 printf ("To quit, type in 'quit'\n");
 
 do {
  scanf ("%s", name);

  printf ("strcmp(name, 'quit') != 0  : %d\n", strcmp(name, "quit") != 0);
  printf ("strcmp(name, 'quit')  :  %d\n", strcmp(name, "quit"));
 } while (strcmp (name, "quit") != 0);

 return 0;
}

The while loop will execute as long as the expression evaluates TRUE (anything non-zero). strcmp() returns zero only if the two strings match, and non-zero if they are different.

Code:

while ( strcmp( "Hello", "World" ) )
{
  /* This executes because strcmp returns non-zero (TRUE) */
}

There is no need to test if TRUE != FALSE :)