Python Program to Print Sum of all Elements in an Array.

Given an array arr[] of integers of size n. Your task is to write a Python program that calculates and prints the sum of all the elements present in the array.

Example:

Input: [3, 8, 12, 5, 2]
Output: The sum of elements is 30

Input: [1, 2, 3, 4, 5]
Output: The sum of elements is 15

Input: [-2, 5, 7, -1, 9]
Output: The sum of elements is 18

There are multiple ways to find the sum of all array elements and in this article, we will learn few of them. 

Approach 1: Sum of Array Elements Using Loop.

One fundamental method to calculate the sum of elements in a Python array involves utilizing a loop structure. This classic approach employs an iterative process to traverse through each element of the array and accumulate the sum.

Algorithm Steps:

• Initialize a variable sum to zero.

• Traverse through each element in the array.

• Add the current element to the running sum.

• After iterating through all elements, return the final sum.

Python Code:

# Python code to find sum of array using loop

#Initialize array
arr = [2, 4, 6, 8, 1]
sum = 0

# Traverse array
for num in arr:
    sum += num

#Print the sum value    
print("Sum of Array Elements: " + str(sum))

Output:

Sum of Array Elements: 21

• Time Complexity: This method operates in linear time, with a complexity of O(n), where 'n' represents the number of elements in the array.

• Space Complexity: The space complexity is constant, denoted as O(1), as only a single variable (sum) is used.

Approach 2: Sum of Array Elements Using sum() Function.

An alternative and concise approach to compute the sum of array elements in Python involves utilizing the built-in sum() function. This function inherently performs the summation, simplifying the code and enhancing readability.

Algorithm Steps:

• Directly apply the sum() function to the array.

• The function internally iterates through each element, calculating the sum.

• Return the computed sum of given array.

Python Code:

# Python code to find sum of array using function

#Initialize array
arr = [2, 4, 6, 8, 3]

# sum funtion of python
arraySum = sum(arr)

#Print the sum value    
print("Sum of Array Elements: " + str(arraySum))

Output:

Sum of Array Elements: 23

• Time Complexity: This approach has a time complexity of O(n), similar to the loop-based method.

• Space Complexity: The space complexity remains O(1) as it returns a single sum value.

There are many other methods to find sum of array in Python but these two are most simpest way to find the sum of array.