Object arrays in PowerShell - Step-by-Step Execution

Concept Flow - Object arrays

Create empty array

↓

Create object

↓

Add object to array

↓

Repeat for each object

↓

Use array of objects

We create objects, add them to an array, and then use the array to access all objects.

Execution Sample

PowerShell

$obj1 = [PSCustomObject]@{Name='Alice'; Age=30}
$obj2 = [PSCustomObject]@{Name='Bob'; Age=25}
$array = @($obj1, $obj2)
$array | ForEach-Object { $_.Name }

Create two objects with Name and Age, put them in an array, then print each Name.

Execution Table

Step	Action	Variable State	Output
1	Create object obj1 with Name='Alice', Age=30	obj1 = {Name=Alice, Age=30}
2	Create object obj2 with Name='Bob', Age=25	obj2 = {Name=Bob, Age=25}
3	Create array with obj1 and obj2	array = [{Name=Alice, Age=30}, {Name=Bob, Age=25}]
4	Loop over array and output Name property	array unchanged	Alice
5	Continue loop	array unchanged	Bob
6	End loop	array unchanged

💡 All objects processed, loop ends.

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	Final
obj1	undefined	{Name=Alice, Age=30}	{Name=Alice, Age=30}	{Name=Alice, Age=30}	{Name=Alice, Age=30}
obj2	undefined	undefined	{Name=Bob, Age=25}	{Name=Bob, Age=25}	{Name=Bob, Age=25}
array	undefined	undefined	undefined	[{Name=Alice, Age=30}, {Name=Bob, Age=25}]	[{Name=Alice, Age=30}, {Name=Bob, Age=25}]

Key Moments - 3 Insights

Why do we use [PSCustomObject] to create objects?

Using [PSCustomObject] creates structured objects with named properties, which can be stored in arrays and accessed easily, as shown in steps 1 and 2.

Can we add objects to the array after creating it?

Yes, but in this example we create the array with objects inside it at once (step 3). You can also add objects later using += operator.

How do we access properties of objects inside the array?

We loop over the array and use $_.PropertyName to access each object's property, as shown in steps 4 and 5.

Visual Quiz - 3 Questions

Look at the execution table, what is the value of obj2 after step 2?

A {Name=Alice, Age=30}

B undefined

C {Name=Bob, Age=25}

D empty array

💡 Hint

Check the 'Variable State' column at step 2 for obj2.

At which step does the array get created with both objects inside?

A Step 1

B Step 3

C Step 2

D Step 4

💡 Hint

Look for the action 'Create array with obj1 and obj2' in the execution table.

If we add a third object to the array, how would the output change in the loop?

A It would print the Name of all three objects

B It would print only the first two Names

C It would cause an error

D It would print nothing

💡 Hint

Refer to how the loop outputs each object's Name property in steps 4 and 5.

Concept Snapshot

Object arrays in PowerShell:
- Create objects with [PSCustomObject]@{Property=Value}
- Store objects in an array: $array = @($obj1, $obj2)
- Access objects with loops: $array | ForEach-Object { $_.Property }
- Arrays hold multiple objects for easy management
- Use properties to get data from each object

Full Transcript

This example shows how to create objects in PowerShell using [PSCustomObject] with named properties like Name and Age. Then, we put these objects into an array. The array holds multiple objects together. We loop through the array using ForEach-Object and print the Name property of each object. Variables obj1 and obj2 hold the individual objects. The array variable holds both objects. The loop runs twice, printing 'Alice' and then 'Bob'. This method helps organize data as objects inside arrays for easy access and processing.