wcsncmp() function in C/C++

The wcsncmp() function in C/C++ compare characters of two wide strings. The comparison is done lexicographically. This function takes three arguments lhs, rhs and count. It compares the contents of lhs and rhs lexicographically upto a maximum of count wide characters.

Note: The behaviour of wcsncmp() is undefined if either of lhs or rhs do not point to null terminated wide strings.

Syntax:

int wcsncmp( const wchar_t* lhs, const wchar_t* rhs, size_t count )

Parameter :The function accepts three mandatory parameters which are described below:

lhs : String to be compared
rhs : String to be compared
count : Maximum number of characters to compare

Return value: The function returns three value as below:

Positive value: if the first differing character in lhs is greater than the corresponding character in rhs.
Negative value: if the first differing character in lhs is less than the corresponding character in rhs.
Zero: if the characters compared in both the strings form the same string.

Below programs illustrate the above function:
Program 1 :

// C++ program to illustrate the 
// wcsncmp() function 
#include <bits/stdc++.h> 
using namespace std; 
  
// function to compare two strings 
void check(wchar_t* lhs, wchar_t* rhs, int count) 
{ 
    int result; 
    // compare lhs and rhs by wcsncmp 
    result = wcsncmp(lhs, rhs, count); 
  
    // print, as per result 
    if (result < 0) 
        wcout << lhs << " precedes " << rhs << "\n"; 
    else if (result > 0) 
        wcout << rhs << " precedes " << lhs << "\n"; 
    else
        wcout << L"First " << count << L" characters of "
              << L" are same"
              << "\n"; 
} 
  
// Driver code 
int main() 
{ 
    // initialize two strings lhs and rhs to compare 
    wchar_t lhs[] = L"geekforgeeks"; 
    wchar_t rhs[] = L"geekGgeek"; 
  
    // check till 4th characters and till 7th characters 
    check(lhs, rhs, 4); 
    check(lhs, rhs, 7); 
  
    return 0; 
} 

Output:

First 4 characters of  are same
geekGgeek precedes geekforgeeks

Program 2 :

// C++ program to illustrate the 
// wcsncmp() function 
#include <bits/stdc++.h> 
using namespace std; 
  
// function to compare two strings 
void check(wchar_t* lhs, wchar_t* rhs, int count) 
{ 
    int result; 
    // compare lhs and rhs by wcsncmp 
    result = wcsncmp(lhs, rhs, count); 
  
    // print, as per result 
    if (result < 0) 
        wcout << lhs << " precedes " << rhs << "\n"; 
    else if (result > 0) 
        wcout << rhs << " precedes " << lhs << "\n"; 
    else
        wcout << L"First " << count << L" characters of "
              << L" are same"
              << "\n"; 
} 
  
// Driver code 
int main() 
{ 
    // initialize two strings lhs and rhs to compare 
    wchar_t lhs[] = L"01234GFG"; 
    wchar_t rhs[] = L"01234GFG"; 
  
    // check till 5th character 
    // and again till 8th character 
    check(lhs, rhs, 5); 
    check(lhs, rhs, 8); 
  
    return 0; 
} 

Output:

First 5 characters of  are same
First 8 characters of  are same

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