Convert-String

Understanding the Convert-String Cmdlet in PowerShell

Welcome back to Wahmans PowerShell Blog! In this post, we’re diving into a unique and often underutilized cmdlet: Convert-String. According to Microsoft, this cmdlet “formats a string to match examples.” But what does that actually mean in practice? In short, Convert-String uses example-driven parsing to transform strings based on given patterns.

This cmdlet is especially useful when you’re trying to reshape or extract data in custom formats. Rather than parsing strings manually with regex or complicated logic, you can define examples of the source and target format, and Convert-String tries to do the rest.

Basic Syntax

Convert-String -InputObject <string> -Example "InputExample=OutputExample"

Example 1: Simple String Conversion

Let’s start with a basic usage. Suppose you have names in “Last, First” format and want them in “First Last” format.

"Doe, John" | Convert-String -Example "Doe, John=John, Doe"

Output:

John Doe

Example 2: Extracting Values from a Pattern

Imagine you have logs with entries like this:

"[INFO] 2024-06-01 User: wahman123"

You want to extract just the username.

$log = "[INFO] 2024-06-01 User: wahman123" | Convert-String -Example "[INFO] Date User: username=username"

Output:

wahman123

Example 3: Batch Processing Multiple Inputs

You can also process multiple lines:

$data = "Smith, Anna", "Brown, James", "Taylor, Sophia" | Convert-String -Example "Last, First=First Last"

Output:


Anna Smith
James Brown
Sophia Taylor

Example 4: Advanced Pattern Matching

Say you have a string containing employee data:

"Name: Jane Smith | ID: 5678 | Dept: IT"

You want just the ID and Department in the format “5678 – IT”:

$emp="Name: Jane Smith | ID: 5678 | Dept: IT"

$emp | Convert-String -Example "Name: FullName | ID: 1234 | Dept: Department=1234 - Department"

Output:

5678 - IT

Wrapping Up

Convert-String is a hidden gem in PowerShell, especially helpful for string transformations when regex feels like overkill. By providing example-based mappings, you can build robust string manipulation logic with minimal code and high readability.

Happy scripting, and I will see you in the next post!

One response to “Convert-String”

  1. Monty Avatar
    Monty

    Just found your blog from your reddit comment: https://www.reddit.com/r/PowerShell/comments/1ljeoxl/comment/mzjnzbv/

    I’ve never heard of Convert-String before, but I can definitely see the utility. What an awesome tip!

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