.cbegin
.cbegin() is a member function of C++ containers (like vector, list, map, etc.) that returns a constant iterator to the first element of the container. This iterator cannot be used to modify the element it points to. It’s commonly used when read-only access to the container’s elements is desired.
.cbegin() is typically used when iterating over a container without modifying its elements. It enforces const-correctness and is a safer choice when the container is const or when preventing accidental modification is desired.
Syntax
container.cbegin();
Parameters:
The .cbegin() function does not take any parameters.
Return value:
Returns a constant iterator that refers to the first element of the container.
Differences Between .begin() and .cbegin()
| Feature | .begin() |
.cbegin() |
|---|---|---|
| Return Type | Mutable iterator | Constant iterator |
| Mutability | Supports modification of elements | Prevents modification of elements |
| Use Case | Suitable when element updates are needed | Ideal for read-only access to elements |
| C++ Version | Available since C++98 | Introduced in C++11 |
Example
In this example, .cbegin() returns a constant iterator that refers to the first element of the array, ensuring that the value cannot be modified through the iterator:
#include <iostream>#include <array>int main() {std::array<int, 5> nums = {10, 20, 30, 40, 50};// Using .cbegin() to get a constant iterator to the beginningstd::array<int, 5>::const_iterator it = nums.cbegin();std::cout << "First element: " << *it << std::endl;return 0;}
The output of this code will be:
First element: 10
Codebyte Example
In this codebyte example, .cbegin() is used to iterate over a vector in read-only mode, preventing accidental modification of its elements:
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