Array in C++
An array is a group of data items with same data type that are stored in a row or column of memory.
For example, if we create an array to store 5 integer values, then each block will only keep the value of an integer data type. If we try to store a float value or anything other than an integer, we will get a compile-time error.

Here,
First Index = 0
Last Index = 4
Array Length = 5
Program to illustrate arrays in C++:
#include <iostream>
using namespace std;
int main()
{
int arr[4] = {5, 10, 25, 32}; // initializing an array of size 4
cout << "Data item at index 3 = " << arr[3] << "\n"; // gives the element at index 3
cout << "Data item at index 2 = " << arr[2]; // gives the element at index 2
return 0;
}
Output
Data item at index 3 = 32
Data item at index 3 = 25
Data item at index 3 = 25
Types of arrays in C++
There are two types of arrays in C++:
- Single Dimensional Array - In this type of array, elements are stored in a single dimension. For example:
#include <iostream>
using namespace std;
int main()
{
int array[5] = {7, 2, 6, 1, 5};
for (int i = 0; i < 5; i++)
{
cout << array[i] << " ";
}
return 0;
}
Output
7 2 6 1 5
#include <iostream>
using namespace std;
int main()
{
int array[3][3] = {{2, 4, 6}, {3, 6, 1}, {5, 7, 7}};
for (int i = 0; i < 3; ++i)
{
for (int j = 0; j < 3; ++j)
{
cout << array[i][j] << " ";
}
cout << "\n"; // newline every row
}
return 0;
cout << endl;
return 0;
}
Output
2 4 6
3 6 1
5 7 7
3 6 1
5 7 7
Advantages of Arrays
Following are some advantages of using arrays in C++:
- Accessing an element is very easy in an array by using the index number.
- Arrays have low overhead.
- Arrays store multiple data of the same types using a single name.