NAME¶

std::basic_string::front - std::basic_string::front

Synopsis¶

CharT& front(); (1) (constexpr since C++20)
const CharT& front() const; (2) (constexpr since C++20)

Returns reference to the first character in the string. The behavior is undefined if
empty() is true.

Parameters¶

(none)

Return value¶

Reference to the first character, equivalent to operator[](0).

Complexity¶

Constant.

Notes¶

In libstdc++, front() is not available in C++98 mode.

Example¶

// Run this code

#include <iostream>
#include <string>

int main()
{
std::string s("Exemplary");
char& f1 = s.front();
f1 = 'e';
std::cout << s << '\n'; // "exemplary"

std::string const c("Exemplary");
char const& f2 = c.front();
std::cout << &f2 << '\n'; // "Exemplary"
}

Output:¶

exemplary
Exemplary

Defect reports

The following behavior-changing defect reports were applied retroactively to
previously published C++ standards.

DR Applied to Behavior as published Correct behavior
LWG 534 C++98 std::basic_string did not have the member added
function front()

See also¶

back accesses the last character
(DR*) (public member function)
front accesses the first character
(public member function of std::basic_string_view<CharT,Traits>)