C++ std::string::find_last_of用法及代码示例

std::string::find_last_of是一个字符串类成员函数，用于查找字符串中任何字符最后一次出现的索引。如果字符存在于字符串中，则返回该字符在字符串中最后一次出现的索引，否则返回string::npos。

头文件：

#include < string >

模板类

template < class T >
size_type
    find_last_of(const T& t, 
                 size_type pos = npos ) const noexcept();

语法1：

find_last_of(char ch)

参数：此函数采用给定字符，并返回该字符最后一次出现的位置。

下面是说明字符串的程序：: find_last_of()：

// C++ program to illustrate string::find_last_of 
#include <cstddef> 
#include <iostream> 
#include <string> 
using namespace std; 
  
// Driver Code 
int main() 
{ 
  
    // Given String 
    string str("Welcome to GeeksforGeeks!"); 
  
    // Character to be found 
    char ch = 'e'; 
  
    // To store the index of last 
    // character found 
    size_t found; 
  
    // Function to find the las 
    // character ch in str 
    found = str.find_last_of(ch); 
  
    // If string doesn't have 
    // character ch present in it 
    if (found == string::npos) { 
        cout << "Character " << ch 
             << " is not present in"
             << " the given string."; 
    } 
  
    // Else print the last position 
    // of the character 
    else { 
        cout << "Character " << ch 
             << " is found at index:"
             << found << endl; 
    } 
}

输出：

Character e is found at index:21

语法2：

find_last_of(char ch, size_t position)

参数：该函数采用给定的字符和索引，直到执行搜索为止。它返回该字符最后一次出现的位置。

下面是说明字符串的程序：: find_last_of()：

// C++ program to illustrate string::find_last_of 
#include <cstddef> 
#include <iostream> 
#include <string> 
using namespace std; 
  
// Driver Code 
int main() 
{ 
  
    // Given String 
    string str("Welcome to GeeksforGeeks!"); 
  
    // Character to be found 
    char ch = 'e'; 
  
    // To store the index of last 
    // character found 
    size_t found; 
  
    // Position till search is performed 
    int pos = 10; 
  
    // Function to find the last 
    // character ch in str[0, pos] 
    found = str.find_last_of(ch, pos); 
  
    // If string doesn't have 
    // character ch present in it 
    if (found == string::npos) { 
        cout << "Character " << ch 
             << " is not present in"
             << " the given string."; 
    } 
  
    // Else print the last position 
    // of the character 
    else { 
        cout << "Character " << ch 
             << " is found at index:"
             << found << endl; 
    } 
}

输出：

Character e is found at index:6

参考文献： http://www.cplusplus.com/reference/string/string/find_last_of/

相关用法

注：本文由纯净天空筛选整理自pranjal_g99大神的英文原创作品 std::string::find_last_of in C++ with Examples。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。