PowerShell Script to Find Sum of Array

Use $sum = ($array | Measure-Object -Sum).Sum to find the sum of an array in PowerShell.

Examples

Input[1, 2, 3]

Output6

Input[10, 20, 30, 40]

Output100

Input[]

Output0

How to Think About It

To find the sum of numbers in an array, think of adding each number one by one. PowerShell provides a simple way to do this using the Measure-Object cmdlet with the -Sum option, which adds all elements automatically.

Algorithm

1

Get the array of numbers.

2

Use a built-in command to calculate the sum of all elements.

3

Store the result in a variable.

4

Output the sum.

Code

powershell

$array = @(1, 2, 3, 4, 5)
$sum = ($array | Measure-Object -Sum).Sum
Write-Output "Sum of array elements is: $sum"

Output

Sum of array elements is: 15

Dry Run

Let's trace the array @(1, 2, 3, 4, 5) through the code

1

Define array

$array = @(1, 2, 3, 4, 5)

2

Calculate sum

$sum = (1 + 2 + 3 + 4 + 5) = 15

3

Output result

Print 'Sum of array elements is: 15'

Array Element	Running Total
1	1
2	3
3	6
4	10
5	15

Why This Works

Step 1: Using Measure-Object

The Measure-Object cmdlet can calculate statistics like sum, count, and average on collections.

Step 2: Piping the array

We send the array elements through the pipeline to Measure-Object to process them.

Step 3: Extracting the sum

The -Sum option tells it to add all numbers, and we access the .Sum property to get the total.

Alternative Approaches

Using a foreach loop

powershell

$array = @(1, 2, 3, 4, 5)
$sum = 0
foreach ($num in $array) {
    $sum += $num
}
Write-Output "Sum of array elements is: $sum"

This method is more manual but helps beginners understand the addition process step-by-step.

Using the .NET Sum() method

powershell

$array = @(1, 2, 3, 4, 5)
$sum = [System.Linq.Enumerable]::Sum($array)
Write-Output "Sum of array elements is: $sum"

This uses .NET's LINQ Sum method, which is concise but requires understanding of .NET classes.

Complexity: O(n) time, O(1) space

Time Complexity

The sum operation must look at each element once, so it takes linear time proportional to the array size.

Space Complexity

No extra space is needed besides a variable to hold the sum, so space is constant.

Which Approach is Fastest?

Using Measure-Object or the .NET Sum method are both efficient and concise; the foreach loop is clear but slightly longer.

Approach	Time	Space	Best For
Measure-Object -Sum	O(n)	O(1)	Quick and readable for beginners
foreach loop	O(n)	O(1)	Learning and understanding addition process
.NET Sum() method	O(n)	O(1)	Concise code with .NET knowledge