Python Program to Find Sum of Array

Given an array of integers, find the sum of its elements. For Examples:

Input: [1, 2, 3]
Output: 6
Explanation: 1 + 2 + 3 = 6

Let's explore different methods to find the sum of an array one by one:

Using sum() Function

Python provides a built-in sum() function to calculate the sum of elements in a list, tuple or set.

arr = [12, 3, 4, 15]
ans = sum(arr)
print('Sum:', ans)

Sum: 34

Using reduce() Method

The reduce() function from functools applies a function cumulatively to the elements of an iterable, effectively summing all elements.

from functools import reduce
arr = [12, 3, 4, 15]
ans = reduce(lambda a, b: a + b, arr)
print('Sum:', ans)

Sum: 34

Explanation: reduce() applies a function cumulatively to items of the iterable, combining them into a single result (here it repeatedly adds pairs).

Using Iteration

Iterating through the array and adding each element to the sum variable and finally displaying the sum.

arr = [12, 3, 4, 15]
t = 0
for x in arr:
    t += x

print('Sum:', t)

Sum: 34

Using enumerate() Function

enumerate() allows looping through an array with an index and element. This method adds each element to a running sum.

arr = [12, 3, 4, 15]
t = 0
for i, val in enumerate(arr):
    t += val

print(t)

34

Explanation: for i, val in enumerate(arr) loop over arr while also receiving the index i (0, 1, 2, ...) and the element val.

Please refer complete article on Program to find sum of elements in a given array for more details!