C++ strncmp() Function

February 8, 2021 9:55 am IST

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C++ strncmp()

The strncmp() function compares the characters of two strings up to the specified length.

The characters of the strings may be in lower case or upper case, this function discriminates between them.

Every character holds an ASCII value (an integer ranging from 0 to 127). For example, 'A' holds the ASCII value of 65 and 'a' holds the ASCII value of 97. So, in the comparison between two strings, their ASCII values are compared.

The strncmp() function starts comparison character by character starting from the first character until the characters in both strings are equal, reached the specified length, or a NULL character is encountered.

This function is defined in <cstring> header file.

Example

C++ Compiler

#include <iostream> #include <cstring> using namespace std; int main() { const char str1[] = "ABCD"; const char str2[] = "abcdABCD"; int res = strncmp(str1, str2, 4); if(res == 0) cout << "str1 is equal to str2"; else if(res > 0) cout << "str1 is greater than str2"; else cout << "str1 is less than str2"; return 0; }

Output

str1 is less than str2

Syntax

int strncmp(const char *str1, const char *str2, int n)

Parameter Values

Value	Type	Explanation
str1	Required	Specifies the string 1
str2	Required	Specifies the string 2
n	Required	Specifies the length up to which the characters in the strings are compared.