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Learn how to effectively build an array in `PowerShell` where each item appears on a new line, ensuring efficient code practices and clear formatting.
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This video is based on the question https://stackoverflow.com/q/68490437/ asked by the user 'Garrett' ( https://stackoverflow.com/u/6692648/ ) and on the answer https://stackoverflow.com/a/68490516/ provided by the user 'AdminOfThings' ( https://stackoverflow.com/u/11025476/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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Mastering PowerShell Arrays: Building Multiline Output from File Names

If you're working with file systems in PowerShell, you might find yourself needing to capture specific parts of file names in an array format. One common scenario is when you use Get-ChildItem to pull file details, but the output results in a single long string instead of the desired multiline array. In this blog, we will explore the problem and provide a solution that ensures each item appears on a new line in your output.

The Problem: Single Long String Output

Let’s say you've written a script that retrieves files modified within the last 22 days. You want to split the base names of these files to create an array that holds each name part on a new line. However, you encounter the following issue:

Current Script Example

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

Current Outcome

When you call $array, the output is:

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

This is not what you wanted. You’re looking for:

Desired Outcome

You want the output to appear as:

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

Understanding the Issue

The reason you're getting a single long string rather than an array is that $array is treated as a string during its first assignment. When you use $array + = $file, you are constantly appending to that original string, rather than adding new elements to an array.

The Solution: Proper Array Creation

Streamlining Your Code

Instead of trying to append to a string, you can make effective use of the foreach statement to build your array directly. Here’s the improved version of your script:

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

In this setup:

You are directly iterating over $files and each split filename is output as an element in the array $array.

The entire process ensures that each value from your specified criteria becomes its own distinct element.

Efficiency Tip

Using the + = operator to extend an array can lead to inefficiencies. Every time you use + =, a new array is created which can slow down your script, especially with larger datasets. Instead, by capturing the results of the foreach output directly, this approach becomes significantly more efficient.

Conclusion

By understanding how PowerShell handles strings and arrays, you can improve the way you manage outputs, especially when dealing with filenames and long strings. Remember to use the foreach method for better practice and efficiency when populating arrays. Now, you can confidently build your arrays in PowerShell that display each item on a new line – just as you intended!

This method not only enhances the clarity of your outputs but also helps in maintaining efficient and clean scripts. Happy scripting!