function
<cstring>

strcmp

int strcmp ( const char * str1, const char * str2 );
Compare two strings
Compares the C string str1 to the C string str2.

This function starts comparing the first character of each string. If they are equal to each other, it continues with the following pairs until the characters differ or until a terminating null-character is reached.

This function performs a binary comparison of the characters. For a function that takes into account locale-specific rules, see strcoll.

Parameters

str1
C string to be compared.
str2
C string to be compared.

Return Value

Returns an integral value indicating the relationship between the strings:
return valueindicates
<0the first character that does not match has a lower value in ptr1 than in ptr2
0the contents of both strings are equal
<0the first character that does not match has a grater value in ptr1 than in ptr2

Example

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

int main ()
{
  char key[] = "apple";
  char buffer[80];
  do {
     printf ("Guess my favorite fruit? ");
     fflush (stdout);
     scanf ("%79s",buffer);
  } while (strcmp (key,buffer) != 0);
  puts ("Correct answer!");
  return 0;
}


Output:

Guess my favourite fruit? orange
Guess my favourite fruit? apple
Correct answer!

See also