std::deque<T,Allocator>::front

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< cpp‎ | container‎ | deque

 
 
Containers library
Sequence
(C++11)
Associative
Unordered associative
Adaptors
Views
(C++20)
 
 
reference front();
const_reference front() const;

Returns a reference to the first element in the container.

Calling front on an empty container is undefined.

Parameters

(none)

Return value

reference to the first element

Complexity

Constant

Notes

For a container c, the expression c.front() is equivalent to *c.begin().

Example

The following code uses front to display the first element of a std::deque<char>:

#include <deque>
#include <iostream>
 
int main()
{
    std::deque<char> letters {'o', 'm', 'g', 'w', 't', 'f'};
 
    if (!letters.empty()) {
        std::cout << "The first character is '" << letters.front() << "'.\n";
    }  
}

Output:

The first character is 'o'.

See also

access the last element
(public member function)