Arrays in PowerShell - Step-by-Step Execution

Concept Flow - Arrays

Create Array

↓

Add Elements

↓

Access Elements by Index

↓

Modify Elements by Index

↓

Use Array in Commands or Loops

↓

End

This flow shows how to create an array, add or access elements by their position, modify them, and use the array in commands or loops.

Execution Sample

PowerShell

$arr = @(10, 20, 30)
$arr[1]
$arr[2] = 40
$arr

Create an array with three numbers, get the second element, change the third element, then show the whole array.

Execution Table

Step	Action	Array State	Output
1	Create array @(10, 20, 30)	[10, 20, 30]
2	Access element at index 1	[10, 20, 30]	20
3	Modify element at index 2 to 40	[10, 20, 40]
4	Output whole array	[10, 20, 40]	10 20 40

💡 All steps completed; array created, accessed, modified, and displayed.

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	Final
$arr	null	[10, 20, 30]	[10, 20, 30]	[10, 20, 40]	[10, 20, 40]

Key Moments - 3 Insights

Why does $arr[1] return 20 and not 10?

Arrays in PowerShell start at index 0, so $arr[0] is 10, $arr[1] is 20 as shown in execution_table step 2.

What happens if I try to access an index that does not exist?

PowerShell returns nothing; in this example, only indexes 0 to 2 exist as seen in variable_tracker and execution_table.

Does modifying $arr[2] change the original array?

Yes, as shown in step 3, $arr[2] changes from 30 to 40, updating the array in place.

Visual Quiz - 3 Questions

Look at the execution table, what is the output when accessing $arr[1]?

A 20

B 10

C 30

D 40

💡 Hint

Check execution_table row 2 under Output column.

At which step does the array change from [10, 20, 30] to [10, 20, 40]?

A Step 1

B Step 3

C Step 2

D Step 4

💡 Hint

Look at execution_table row 3 and variable_tracker after Step 3.

If you add a new element $arr += 50 after step 4, what will be the final array?

A [10, 20, 40]

B [50]

C [10, 20, 40, 50]

D [10, 20, 30, 50]

💡 Hint

Adding with += appends the element, extending the array.

Concept Snapshot

Arrays in PowerShell:
- Created with @() syntax
- Index starts at 0
- Access elements with $arr[index]
- Modify elements by assigning $arr[index] = value
- Use arrays in loops or commands
- Adding elements with += appends to array

Full Transcript

This lesson shows how to work with arrays in PowerShell. First, you create an array using @() with elements inside. Then you can get an element by its position using square brackets, remembering that counting starts at zero. You can change an element by assigning a new value to that position. Finally, you can output the whole array to see all elements. Arrays are useful to store lists of items and use them in scripts or loops.