A comparison is an expression that results in True or False based on two values. There are many operators, and they can be compare many different types of values.

Using Operators to Compare Values

Most of these operators are similar to each other. PowerShell is generally case insensitive, because of its Windows-based origins. Operations on strings are case agnostic unless the case-sensitive operator (prefixed by “c”) is used.

$num1 = 10
$num1 -eq 10

'Hello' -eq 'hello'
'Hello' -ceq 'hello'

In PowerShell, lowercase letters are considered less than uppercase letters when you compare them.

-Like and -Match can confuse many people on how they evaluate. -like searches for a wildcard string, while -match uses regular expressions. For instanace, wildcards might catch everything before or after a string but RegEx can capture something more granular, like everything that contains a specific pattern of characters and symbols. It’s easier to see in practice. Check out an online regex builder like RegExr or RegEx101 if you want to dive into that.

$text = "The quick brown fox jumps over the lazy dog."
$pattern = "*b*"
$text -like $pattern

$text = "The quick brown fox jumps over the lazy dog."
$pattern = "\b[bB]\w+\b" # This matches any word starting with 'b' or 'B'
$text -match $pattern

Finally, -Contains and -In can be confusing. -Contains looks for a value in a collection of values, and -In looks for a collection in another value. This essentially looks for the same thing in different directions.

$cities = "New York", "Los Angeles", "Chicago", "Houston", "Philadelphia"
$cities -Contains 'New York'

$cities = "New York", "Los Angeles", "Chicago", "Houston", "Philadelphia"
"New York" -In $cities

The best use case for comparisons is for triggering conditional statements, which fire if something is true or false. We’ll cover that next.