C++ std::array::cend

The std::array::cend function returns a constant iterator pointing to one past the last element of the array. This iterator ensures read-only access to the array elements and is typically used with cbegin() to traverse the array in a safe, non-modifiable manner.

Syntax of std::array::cend

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const_iterator cend() const noexcept;

Parameters

The std::array::cend function does not take any parameters.

Return Value

Returns a constant iterator pointing to one past the last element of the array. This marks the end of the array when traversing with constant iterators.

Examples for std::array::cend

Example 1: Traversing an Array Using std::array::cend

This example demonstrates iterating through the elements of a std::array using cbegin() and cend():

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#include <iostream>
#include <array>

int main() {
    std::array<int, 5> arr = {10, 20, 30, 40, 50};

    std::cout << "Array elements: ";
    for (auto it = arr.cbegin(); it != arr.cend(); ++it) {
        std::cout << *it << " ";
    }
    std::cout << std::endl;

    return 0;
}

Explanation:

  1. Define an array: A std::array of size 5 is defined and initialized with the elements {10, 20, 30, 40, 50}.
  2. Use cend(): The cend() function provides a constant iterator pointing to one past the last element of the array.
  3. Iterate through the array: A for loop is used to traverse the array, with cbegin() as the starting point and cend() as the endpoint.
  4. Read-only access: The constant iterators ensure that the array elements cannot be modified during iteration.

Output:

Array elements: 10 20 30 40 50

Example 2: Using std::array::cend with a Standard Algorithm

This example demonstrates using std::array::cend with the std::find algorithm to locate an element in a std::array:

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#include <iostream>
#include <array>
#include <algorithm>

int main() {
    std::array<int, 5> arr = {1, 2, 3, 4, 5};

    int target = 3;
    auto it = std::find(arr.cbegin(), arr.cend(), target);

    if (it != arr.cend()) {
        std::cout << "Element " << target << " found at position " 
                  << std::distance(arr.cbegin(), it) << std::endl;
    } else {
        std::cout << "Element " << target << " not found." << std::endl;
    }

    return 0;
}

Explanation:

  1. Original array: The array arr is initialized with elements {1, 2, 3, 4, 5}.
  2. Use std::find: The std::find algorithm searches for the target element in the range defined by cbegin() and cend().
  3. Check the result: If the element is found, the iterator it points to its position. The std::distance function calculates its index.
  4. Output the result: The result of the search is displayed, indicating whether the element was found and, if so, its position.

Output:

Element 3 found at position 2

Exception Handling in std::array::cend

The std::array::cend function does not throw exceptions as it is marked noexcept. This ensures safe usage when accessing the end of a constant iterator range.