Solving Common PowerShell Issues: Iterating Multiple Variables with Arrays

Discover how to efficiently iterate over arrays in PowerShell, addressing common pitfalls when assigning values from one array to another.
---

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: PowerShell: Iterating Multiple Variables not working as expected

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Solving Common PowerShell Issues: Iterating Multiple Variables with Arrays

When working with PowerShell, managing and manipulating data using arrays is a common task. However, many users face challenges, especially when it comes to iterating over arrays and assigning values dynamically. In this post, we will explore a common problem: how to populate empty values in an array based on values from another array. Let's dive into the problem and a streamlined solution.

Understanding the Problem

In your PowerShell script, you have two arrays:

$dailyTasks which holds tasks and employee names.

$randomisedUsers that contains employee names which you want to use to fill in any empty entries in the EmployeeName field of $dailyTasks.

Example Data Structure

Here's an example of what your $dailyTasks array looks like before running any scripts:

TaskEmployeeNameEmployeeName2Task1Task2Person YTask3Task4Person ZPerson XThe goal is to replace any empty EmployeeName field with names from $randomisedUsers. However, your initial approach did not yield the desired results when trying to fill in the names.

Analyzing the Original Script

Your original PowerShell script was structured using for loops to iterate through $dailyTasks and assign names from $randomisedUsers. However, the results were not as expected. The key issue was that the assignment logic did not correctly handle multiple possibilities in the $_.Group.EmployeeName.

The Problematic Code Snippet

[[See Video to Reveal this Text or Code Snippet]]

In the code above, when multiple names are available, the nested loop assigns the last name in the list repeatedly to the employee name fields. Therefore, the reason you're not getting Person B is due to overwriting each time.

A Streamlined Solution

To achieve the desired outcome of efficiently filling in the employee names from an array, a simpler approach utilizes PowerShell's capabilities. Here’s a refined way to accomplish this:

Updated PowerShell Script

[[See Video to Reveal this Text or Code Snippet]]

Code Explanation

Convert Input Data: The data for dailyTasks is now stored as CSV, allowing easy manipulation.

Using ArrayList: Instead of a fixed size array, you use an ArrayList, which allows for dynamic resizing (adding/removing elements).

Iterative Filling:

The loop checks if the EmployeeName is empty or consists only of white spaces.

If it's empty, it replaces it with the first name in the $fillEmployees and removes that name from the list to prevent reuse.

Final Thoughts

Working with arrays in PowerShell can be less daunting when approached methodically. This refined script ensures empty fields are filled in without leaving out any names unintentionally. Remember to always use ArrayList for dynamic collections when you need to modify their size. This will solve many iteration issues and improve efficiency in your scripts.

Feel free to experiment further and ask questions if you run into other challenges. Happy scripting!