std::string_view front() method

since C++17

// Const version only
constexpr const_reference front() const;

Returns a reference

to the first character in the view.

Undefined Behavior

Calling front() on an empty view is undefined behavior

.

Parameters

(none)

Return value

Reference to the first character.

Complexity

Constant - O(1).

Notes

For a view str, the expression str.front() is equivalent to *str.begin() and str[0].

Example

Main.cpp

#include <string_view>
#include <iostream>
 
int main() {
    for (std::string_view str{"ABCDEF"}; !str.empty(); str.remove_prefix(1))
        std::cout << str.front() << ' ' << str << '\n';
}

Output

A ABCDEF
B BCDEF
C CDEF
D DEF
E EF
F F