Can you provide examples of using std::vector in C++?

Can you provide examples of using std::vector in C++?

Sure! The std::vector is a dynamic array that can resize itself. Here's a simple example:

#include <iostream>
#include <vector>

int main() {
    std::vector<int> numbers;
    numbers.push_back(10);
    numbers.push_back(20);
    numbers.push_back(30);

    for(int num : numbers) {
        std::cout << num << " ";
    }
    return 0;
}

This code creates a vector of integers and adds three numbers to it.

What are some common methods used with std::vector?

Some common methods include:

• push_back(): Adds an element to the end.
• pop_back(): Removes the last element.
• size(): Returns the number of elements.
• at(): Accesses an element at a specific index safely.
• clear(): Removes all elements from the vector.

Can you explain how to iterate over a std::vector?

Certainly! You can iterate over a std::vector using a range-based for loop or an index-based for loop. Here’s an example using both:

// Range-based for loop
for (int num : numbers) {
    std::cout << num << " ";
}

// Index-based for loop
for (size_t i = 0; i < numbers.size(); ++i) {
    std::cout << numbers[i] << " ";
}

What happens if I try to access an out-of-bounds index?

If you access an out-of-bounds index using the operator[], it leads to undefined behavior. However, if you use the at() method, it throws an std::out_of_range exception, which is safer.