C++ wcsncmp()用法及代碼示例

C /C++中的wcsncmp()函數比較兩個寬字符串的字符。比較是按字典順序進行的。此函數采用三個參數lhs，rhs和count。它按字典順序比較了lhs和rhs的內容，最多可計數寬字符。

注意：如果lhs或rhs都不指向以null終止的寬字符串，則wcsncmp()的行為是不確定的。

用法:

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

參數：該函數接受三個強製性參數，如下所述：

lhs : 要比較的字符串
rhs : 要比較的字符串
count : 要比較的最大字符數

返回值：該函數返回三個值，如下所示：

正值：如果lhs中的第一個不同字符大於rhs中的相應字符。
負值：如果lhs中的第一個不同字符小於rhs中的相應字符。
零：如果兩個字符串中比較的字符形成相同的字符串。

以下示例程序旨在說明上述函數：
示例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; 
}

輸出：

First 4 characters of  are same
geekGgeek precedes geekforgeeks

示例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; 
}

輸出：

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

相關用法

注：本文由純淨天空篩選整理自AmanSrivastava1大神的英文原創作品 wcsncmp() function in C/C++。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。