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std::basic_string::front

性病：基本[医]弦乐：正面

CharT& front(​(since C++11)
const CharT& front() const;​(since C++11)

返回对字符串中第一个字符的引用。如果empty() == true...

参数

%280%29

返回值

引用第一个字符，相当于operator[](0)...

复杂性

常量。

例

二次

#include <iostream>
#include <string>
 
int main()
{
  {
    std::string s("Exemplary"
    char& f = s.front(
    f = 'e';
    std::cout << s << '\n'; // "exemplary"
  }
 
  {
    std::string const c("Exemplary"
    char const& f = c.front(
    std::cout << &f << '\n'; // "Exemplary"
  }
}

二次

产出：

二次

exemplary
Exemplary

二次

另见

back (C++11)accesses the last character (public member function)

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