在c++中,如何知道字符串是否以另一个字符串结束?


当前回答

std::mismatch方法可以用于从两个字符串的末尾开始向后迭代:

const string sNoFruit = "ThisOneEndsOnNothingMuchFruitLike";
const string sOrange = "ThisOneEndsOnOrange";

const string sPattern = "Orange";

assert( mismatch( sPattern.rbegin(), sPattern.rend(), sNoFruit.rbegin() )
          .first != sPattern.rend() );

assert( mismatch( sPattern.rbegin(), sPattern.rend(), sOrange.rbegin() )
          .first == sPattern.rend() );

其他回答

bool endswith(const std::string &str, const std::string &suffix)
{
    string::size_type totalSize = str.size();
    string::size_type suffixSize = suffix.size();

    if(totalSize < suffixSize) {
        return false;
    }

    return str.compare(totalSize - suffixSize, suffixSize, suffix) == 0;
}

另一种选择是使用正则表达式。下面的代码使搜索对大小写不敏感:

bool endsWithIgnoreCase(const std::string& str, const std::string& suffix) {
  return std::regex_search(str,
     std::regex(std::string(suffix) + "$", std::regex_constants::icase));
}

可能不是很有效,但是很容易实现。

使用std::string::compare:比较最后n个字符:

#include <iostream>

bool hasEnding (std::string const &fullString, std::string const &ending) {
    if (fullString.length() >= ending.length()) {
        return (0 == fullString.compare (fullString.length() - ending.length(), ending.length(), ending));
    } else {
        return false;
    }
}

int main () {
    std::string test1 = "binary";
    std::string test2 = "unary";
    std::string test3 = "tertiary";
    std::string test4 = "ry";
    std::string ending = "nary";

    std::cout << hasEnding (test1, ending) << std::endl;
    std::cout << hasEnding (test2, ending) << std::endl;
    std::cout << hasEnding (test3, ending) << std::endl;
    std::cout << hasEnding (test4, ending) << std::endl;

    return 0;
}

std::mismatch方法可以用于从两个字符串的末尾开始向后迭代:

const string sNoFruit = "ThisOneEndsOnNothingMuchFruitLike";
const string sOrange = "ThisOneEndsOnOrange";

const string sPattern = "Orange";

assert( mismatch( sPattern.rbegin(), sPattern.rend(), sNoFruit.rbegin() )
          .first != sPattern.rend() );

assert( mismatch( sPattern.rbegin(), sPattern.rend(), sOrange.rbegin() )
          .first == sPattern.rend() );
bool EndsWith(const std::string& data, const std::string& suffix)
{
    return data.find(suffix, data.size() - suffix.size()) != std::string::npos;
}

测试

#include <iostream>
int main()
{
   cout << EndsWith(u8"o!hello!1", u8"o!") << endl; 
   cout << EndsWith(u8"o!hello!", u8"o!") << endl; 
   cout << EndsWith(u8"hello!", u8"o!") << endl; 
   cout << EndsWith(u8"o!hello!o!", u8"o!") << endl; 
   return 0;
}

输出

0 
1 
1 
1