std::strcmp

 

C++

Language

Standard Library Headers

Freestanding and hosted implementations

Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (C++17)

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Technical Specifications

 

Strings library

Null-terminated strings

Byte strings

Multibyte strings

Wide strings

Classes

basic_string

basic_string_view (C++17)

char_traits

 

Null-terminated byte strings

Functions
Character manipulation
isalnum isalpha islower isupper isdigit isxdigit isblank (C++11)	iscntrl isgraph isspace isprint ispunct tolower toupper
Conversions to numeric formats
atof atoiatolatoll (C++11) strtolstrtoll (C++11)	strtoulstrtoull (C++11) strtofstrtodstrtold (C++11)(C++11) strtoimaxstrtouimax (C++11)(C++11)
String manipulation
strcpy
strncpy
strcat
strncat
strxfrm
String examination
strlen strcmp strncmp strcoll strchr strrchr	strspn strcspn strpbrk strstr strtok
Memory manipulation
memchr
memcmp
memset
memcpy
memmove
Miscellaneous
strerror

 

Defined in header <cstring>
int strcmp( const char *lhs, const char *rhs );

Compares two null-terminated byte strings lexicographically.

The sign of the result is the sign of the difference between the values of the first pair of characters (both interpreted as unsigned char) that differ in the strings being compared.

The behavior is undefined if lhs or rhs are not pointers to null-terminated strings.

Parameters

lhs, rhs

-

pointers to the null-terminated byte strings to compare

Return value

Negative value if lhs appears before rhs in lexicographical order.

Zero if lhs and rhs compare equal.

Positive value if lhs appears after rhs in lexicographical order.

Example

Run this code

#include <vector>
#include <cstring>
#include <algorithm>
#include <iostream>
 
int main() 
{
    std::vector<const char*> cats {"Heathcliff", "Snagglepuss", "Hobbes", "Garfield"};
    std::sort(cats.begin(), cats.end(), [](const char *strA, const char *strB) {
        return std::strcmp(strA, strB) < 0;
    }); 
 
    for (const char *cat : cats) {
        std::cout << cat << '\n';
    }
}

Output:

Garfield
Heathcliff
Hobbes
Snagglepuss

See also

strncmp	compares a certain number of characters from two strings (function)
wcscmp	compares two wide strings (function)
memcmp	compares two buffers (function)
strcoll	compares two strings in accordance to the current locale (function)
C documentation for strcmp