Understanding Powershell Variables

Overview:

The following section explains variables and how they are utilized within PowerShell

Declaring and Using Variables

What is a Variable?

A variable is a storage location identified by a name, used to hold data that can be referenced and manipulated in a script.

Declaring Variables:

In PowerShell, variables are declared using the $ symbol followed by the variable name.
Example:
```
$myVariable = "Hello, World!"
```

Using Variables:

Once declared, variables can be used in commands and scripts.

Example:

$greeting = "Hello, World!"
Write-Output $greeting

Modifying Variables:

Variables can be updated or modified.

Example:

$counter = 10
$counter = $counter + 1
Write-Output $counter

Common Data Types

Strings:

Text data enclosed in quotes.
Example:
```
$name = "John Doe"
```

Integers:

Whole numbers.
Example:
```
$age = 30
```

Arrays:

Ordered collections of values.
Example:
```
$colors = @("Red", "Green", "Blue")
```

Hashtables:

Collections of key-value pairs.

Example:

$person = @{
    Name = "John Doe"
    Age = 30
    Occupation = "Developer"
}

Booleans:

True/False values.
Example:
```
powershellCopy code$isAdmin = $true
```

Examples of Using Different Data Types:

# String
$greeting = "Hello, PowerShell!"

# Integer
$year = 2024

# Array
$fruits = @("Apple", "Banana", "Cherry")

# Hashtable
$book = @{
    Title = "PowerShell Guide"
    Author = "Jane Smith"
    Year = 2024
}

# Boolean
$isComplete = $false

Variable Scopes

Understanding Scope:

Scope determines the visibility and lifetime of a variable.
Common scopes in PowerShell:
- Global: Visible in all scripts and scopes.
- Local: Visible only within the current script or function.
- Script: Visible in the current script file.
- Private: Visible only within the current block or function.

Example of Variable Scopes:

# Global Scope
$Global:globalVar = "I am global"

# Script Scope
$Script:scriptVar = "I am script"

# Local Scope (default)
$localVar = "I am local"

# Private Scope
function Test-Scope {
    $Private:privateVar = "I am private"
    Write-Output $privateVar
}

Test-Scope
Write-Output $privateVar  # This will not work outside the function

Using Scopes Effectively:

Define variables in the appropriate scope based on their intended use.
Be mindful of scope to avoid conflicts and unexpected behaviors.

Last updated 1 year ago