strcmp

Compare strings

View other versions (3)

Contents

Interface
Description
Return Values
See Also
Standards
Page Comments

Interface

#include <string.h>int  strcmp (const char *s1, const char *s2)
int  strncmp (const char *s1, const char *s2, size_t len)

Description

The strcmp and strncmp functions lexicographically compare the null-terminated strings s1 and s2.

The strncmp function compares not more than len characters. Because strncmp is designed for comparing strings rather than binary data, characters that appear after a \0 character are not compared.

Example:

Example - Compare strings

Workings

#include <stdio.h>
#include <string.h>
int main()
{
  // define two strings s, t and initialize s
  char s[10] = "testing", t[10];
  // copy s to t
  strcpy(t, s);
  // test if s is identical to t
  if (!strcmp(s, t))
    printf("The strings are identical.");
  else
    printf("The strings are different.");
 
  return 0;
}

Solution

Output:

The strings are identical.

Return Values

The strcmp and strncmp return an integer greater than, equal to, or less than 0, according as the string s1 is greater than, equal to, or less than the string s2. The comparison is done using unsigned characters, so that \200 is greater than \0.

Standards

The strcmp and strncmp functions conform to ISO/IEC 9899:1990 ("ISO C90").

int	`strcmp` (const char s1, const char s2)
int	`strncmp` (const char s1, const char s2, size_t len)