**Problem Statement:** Given an array, we have to find the sum of all the elements in the array.

**Examples**:

Example 1:Input:N = 5, array[] = {1,2,3,4,5}Output:15Explanation:Sum of all the elements is 1+2+3+4+5 = 15Example 2:Input:N=6, array[] = {1,2,1,1,5,1}Output:11Explanation:Sum of all the elements is 1+2+1+1+5+1 = 11

** Disclaimer**:

*Don’t jump directly to the solution, try it out yourself first.*

**Solution 1: Using for loop**

**Approach**:

- Using for loop traverse through the array and while traversing maintain a variable for storing sum of the elements in the array.
- After completing the traversal simply print the sum.

**Code:**

## C++ Code

```
#include<bits/stdc++.h>
using namespace std;
int main() {
int n = 5;
vector<int>arr = {1, 2, 3, 4, 5};
int sum = 0;
for (int i = 0; i < n; i++) {
sum += (double)arr[i];
}
cout <<"The sum of the elements of the array is "<< sum;
}
```

**Output:**

The sum of the elements of the array is 15

**Time Complexity: **O(n) As we traverse the array once.

**Space Complexity: **O(1).

## Java Code

```
import java.util.*;
public class Main {
public static void main(String args[]) {
int n = 5;
int arr[] = {1,2,3,4,5};
int sum = 0;
for (int i = 0; i < n; i++) {
sum += arr[i];
}
System.out.println("The sum of the elements of the array is "+sum);
}
}
```

**Output:**

The sum of the elements of the array is 15

**Time Complexity: **O(n) As we traverse the array once.

**Space Complexity: **O(1).

**Solution 2: Using collection in Java or STL in C++**

**Approach:**

**For C++:** “accumulate” is used to calculate the sum of all the elements in the array.

**For Java:** Instream sum() gives the sum of all the elements in the stream.

**Code:**

## C++ Code

```
#include<bits/stdc++.h>
using namespace std;
int main() {
int n = 5;
int arr[] = {1, 2, 3, 4, 5};
int initialSum = 0;
cout <<"The sum of the elements of the array is ";
cout<<accumulate(arr, arr + n, initialSum);
}
```

**Output:**

The sum of the elements of the array is 15

**Time Complexity:** O(n).

**Space Complexity:** O(1).

## Java Code

```
import java.util.*;
import java.util.stream.IntStream;
public class Main {
public static void main(String args[]) {
int n = 5;
int arr[] = {1,2,3,4,5};
int sum = IntStream.of(arr).sum();
System.out.println("The sum of the elements of the array is "+sum);
}
}
```

**Output:**

The sum of the elements of the array is 15

**Time Complexity:** O(n).

**Space Complexity:** O(1).

Special thanks to Pranav Padawe for contributing to this article on takeUforward. If you also wish to share your knowledge with the takeUforward fam,please check out this article