Creating a Vector

Part of the Logic & Flow section of Coddy's C++ journey — lesson 10 of 56.

Now that you understand what vectors are, let's learn how to actually create them. There are several ways to declare and initialize a std::vector, depending on your needs.

The most basic approach is to create an empty vector that you can fill later:

std::vector<int> numbers;

This creates an empty vector called numbers that can hold integers. Notice the angle brackets <int> — this tells the vector what type of data it will store.

You can also initialize a vector with values right from the start using an initializer list:

std::vector<int> scores = {85, 92, 78, 96, 88};

This creates a vector with five integers already in it. The curly braces contain the initial values, separated by commas.

Vectors can hold different data types — just change what's inside the angle brackets. For example, std::vector<string> for text or std::vector<double> for decimal numbers. The flexibility of vectors makes them perfect for storing collections of data when you need the convenience of automatic resizing.

Challenge

Easy

Create a program that demonstrates vector initialization by creating a vector of integers with predefined values and displaying its contents.

The following inputs will be provided:

Five integers that should be used to initialize the vector

Your program should:

Create a std::vector<int> named numbers and initialize it with the five input values using an initializer list
Print each element of the vector on a separate line in the exact format shown below
After printing all elements, print the total number of elements in the vector

Use the following exact output format:

Element 0: [first value]
Element 1: [second value]
Element 2: [third value]
Element 3: [fourth value]
Element 4: [fifth value]
Vector size: 5

Access the vector elements using the square bracket [] operator with indices 0 through 4 to print each value. Use the .size() method to get the number of elements in the vector.

Cheat sheet

To create a std::vector, specify the data type in angle brackets:

std::vector<int> numbers;  // Empty vector

Initialize a vector with values using an initializer list:

std::vector<int> scores = {85, 92, 78, 96, 88};

Access vector elements using square brackets with indices:

scores[0]  // First element
scores[1]  // Second element

Get the number of elements using .size():

scores.size()  // Returns number of elements

Vectors can hold different data types by changing the type in angle brackets:

std::vector<string> for text
std::vector<double> for decimal numbers

Try it yourself

#include <iostream>
#include <vector>
using namespace std;

int main() {
    // Read input values
    int val1, val2, val3, val4, val5;
    cin >> val1 >> val2 >> val3 >> val4 >> val5;
    
    // TODO: Write your code below
    // Create a vector named 'numbers' and initialize it with the input values
    // Print each element using the required format
    // Print the vector size
    
    return 0;
}