Problem Definition

Make a Python Function which takes an array or list as input and returns the sum of its elements, for example  array[ 1, 2, 3, 4] will return 1 + 2 + 3 + 4 = 10

Solution

In this article, we will go through two different methods of tackling the same problem.

Method 1: Using loop

In this method first, we are creating a variable total to store the sum and initializing it to 0. Next, the for loop iterates over each element of the array / list and storing their sum in the total variable, at last function returns the total.

def array_summer(arr):
    total = 0
    for item in arr:
        # shorthand of total = total + item
        total += item
    return total

#  Test input
print(array_summer([1, 2, 3, 3, 7]))

Output:

16

Method 2: Using Python's built-in function sum() [ Recommended ]

Python comes with an in-built solution for adding items of iterable (list, tuple, dictionary), the sum() method simply returns the sum of each item of the gives list or array.

def array_summer(arr):
    return sum(arr)

#  Test input
print(array_summer([1, 2, 3, 3, 7]))

Output:

16

we went through two different methods of summing the elements of an array however using sum() function made our code more compact and faster, for a very large list sum() is more efficient therefore it's the recommended way.