C++字符大小写转换 - string类

最近看到了一个用来转换字符大小写比较方便的函数。分享一下！

#include<iostream>
#include<string>
#include<algorithm>
using namespace std;
int main() {
 string s="abcedf";
 transform(s.begin(), s.end(), s.begin(), toupper);//转换成大写
 cout << s << endl;
 transform(s.begin(), s.end(), s.begin(), tolower);//转换成小写
 cout << s << endl;
}

transform函数原型

template < class InputIterator, class OutputIterator,
 class UnaryOperator >  
      OutputIterator transform ( InputIterator first1, InputIterator last1,  
                                 OutputIterator result, UnaryOperator op );  
      
    template < class InputIterator1, class InputIterator2,  
               class OutputIterator, class BinaryOperator >  
      OutputIterator transform ( InputIterator1 first1, InputIterator1 last1,  
                                 InputIterator2 first2, OutputIterator result,  
                                 BinaryOperator binary_op );

参考文章：https://www.cnblogs.com/balingybj/p/4678850.html