Vector Basics
Basic Vector Operations in C++
BeginnerTopic: STL Containers Programs
C++ Vector Basics Program
This program helps you to learn the fundamental structure and syntax of C++ programming.
#include <iostream>
#include <vector>
using namespace std;
int main() {
// Create vector
vector<int> vec;
// Add elements
vec.push_back(10);
vec.push_back(20);
vec.push_back(30);
vec.push_back(40);
vec.push_back(50);
cout << "Vector elements: ";
for (int i = 0; i < vec.size(); i++) {
cout << vec[i] << " ";
}
cout << endl;
// Access elements
cout << "First element: " << vec.front() << endl;
cout << "Last element: " << vec.back() << endl;
cout << "Element at index 2: " << vec.at(2) << endl;
// Size and capacity
cout << "Size: " << vec.size() << endl;
cout << "Capacity: " << vec.capacity() << endl;
// Initialize vector with values
vector<int> vec2 = {1, 2, 3, 4, 5};
cout << "\nVector 2: ";
for (int num : vec2) {
cout << num << " ";
}
cout << endl;
// Remove last element
vec.pop_back();
cout << "\nAfter pop_back: ";
for (int num : vec) {
cout << num << " ";
}
cout << endl;
return 0;
}Output
Vector elements: 10 20 30 40 50 First element: 10 Last element: 50 Element at index 2: 30 Size: 5 Capacity: 8 Vector 2: 1 2 3 4 5 After pop_back: 10 20 30 40
Understanding Vector Basics
Vector is a dynamic array that can resize automatically. It provides random access, efficient insertion/deletion at the end. Key operations: push_back(), pop_back(), size(), capacity(), front(), back(), at(). Vectors store elements contiguously in memory, making them cache-friendly. They automatically manage memory allocation.
Note: To write and run C++ programs, you need to set up the local environment on your computer. Refer to the complete article Setting up C++ Development Environment. If you do not want to set up the local environment on your computer, you can also use online IDE to write and run your C++ programs.