Comparison operators are needed to create expressions and conditions. Comparison operators are always between two objects, one on the left and one on the right. All of them return a Boolean value, either $true or $false, unless you don't compare a list of objects. In the latter scenario most operators would return the matching objects. For all of the comparison operations, there are additional keywords available to work case-sensitive (leading c character) or explicitly case-insensitive (leading i character). Case-sensitivity is a feature to not ignore upper and lower cases between two variables. Default operators work case-insensitive and are marked in bold. This gives you simple guidance. For the first steps, you only need to know about the operators in bold, because you will very rarely need to use the other ones:
|
Operator
|
Meaning
|
Description
|
|
-eq
|
Equals |
Returns equality between left and right value. |
|
-ieq
|
Equals—explicitly case-insensitive |
Returns equality - explicitly case-insensitive. |
|
-ceq
|
Equals—case-sensitive |
Returns equality - case-sensitive. |
|
-ne
|
Not equal |
Returns equality - negated. |
|
-ine
|
Not equal—explicitly case-insensitive |
Returns equality - negated - explicitly case-insensitive. |
|
-cne
|
Not equal—case-sensitive |
Returns equality - negated - case-sensitive. |
|
-gt
|
Greather-than |
Returns if left value is greater than right one. |
|
-igt
|
Greather-than - explicitly case-insensitive |
Returns if left value is greater than right one - explicitly case-insensitive. |
|
-cgt
|
Greather-than - case-sensitive |
Returns if left value is greater than right one - case-sensitive. |
|
-ge
|
Greater-than or equal to |
Returns if left value is greater than or equal to right one. |
|
-ige
|
Greater-than or equal to - explicitly case-insensitive |
Returns if left value is greater than or equal to right one - explicitly case-insensitive. |
|
-cge
|
Greater-than or equal to - case-sensitive |
Returns if left value is greater than or equal to right one - case-sensitive. |
|
-lt
|
Less-than |
Returns if left value is less than right one. |
|
-ilt
|
Less-than - explicitly case-insensitive |
Returns if left value is less than right one - explicitly case-insensitive. |
|
-clt
|
Less-than - case-sensitive |
Returns if left value is less than right one - case-sensitive. |
|
-le
|
Less-than or equal to |
Returns if left value is less than or equal to right one. |
|
-ile
|
Less-than or equal to - explicitly case-insensitive |
Returns if left value is less than or equal to right one - explicitly case-insensitive. |
|
-cle
|
Less-than or equal to - case-sensitive |
Returns if left value is less than or equal to right one - case-sensitive. |
|
-like
|
Matching a defined filter |
Returns if left value is similar to right one, using a filter/wildcard. |
|
-ilike
|
Matching a defined filter - explicitly case-insensitive |
Returns if left value is similar to right one, using a filter/wildcard - explicitly case-insensitive. |
|
-clike
|
Matching a defined filter - case-sensitive |
Returns if left value is similar to right one, using a filter/wildcard - case-sensitive. |
|
-notlike
|
Not matching a defined filter |
Returns if left value is not similar to right one, using a filter/wildcard. |
|
-inotlike
|
Not matching a defined filter - explicitly case-insensitive |
Returns if left value is not similar to right one, using a filter/wildcard - explicitly case-insensitive. |
|
-cnotlike
|
Not matching a defined filter - case-sensitive |
Returns if left value is not similar to right one, using a filter/wildcard - case-sensitive. |
|
-match
|
Matching a defined RegEx filter |
Returns if left value is similar to right one, using RegEx. |
|
-imatch
|
Matching a defined RegEx filter - explicitly case-insensitive |
Returns if left value is similar to right one, using RegEx - explicitly case-insensitive. |
|
-cmatch
|
Matching a defined RegEx filter - case-sensitive |
Returns if left value is similar to right one, using RegEx - case-sensitive. |
|
-notmatch
|
Not matching a defined RegEx filter |
Returns if left value is not similar to right one, using RegEx. |
|
-inotmatch
|
Not matching a defined RegEx filter - explicitly case-insensitive |
Returns if left value is not similar to right one, using RegEx - explicitly case-insensitive. |
|
-cnotmatch
|
Not matching a defined RegEx filter - case-sensitive |
Returns if left value is not similar to right one, using RegEx - case-sensitive. |
|
-contains
|
Collection containing an object |
Returns if left collection contains one object, same as the right one. |
|
-icontains
|
Collection containing an object - explicitly case-insensitive |
Returns if left collection contains one object, same as the right one - explicitly case-insensitive. |
|
-ccontains
|
Collection containing an object - case-sensitive |
Returns if left collection contains one object, same as the right one - case-sensitive. |
|
-notcontains
|
Collection not containing an object |
Returns if left collection does not contain one object, same as the right one. |
|
-icontains
|
Collection not containing an object - explicitly case-insensitive |
Returns if left collection does not contain one object, same as the right one - explicitly case-insensitive. |
|
-cnotcontains
|
Collection not containing an object - case-sensitive |
Returns if left collection does not contain one object, same as the right one - case-sensitive. |
|
-in
|
Value is in a collection of reference values |
Returns if left object is included in collection on the right. |
|
-iin
|
Value is in a collection of reference values - explicitly case-insensitive |
Returns if left object is included in collection on the right - explicitly case-insensitive. |
|
-cin
|
Value is in a collection of reference values - case-sensitive |
Returns if left object is included in collection on the right - case-sensitive. |
|
-notin
|
Value is not in a collection of reference values |
Returns if left object is not included in collection on the right |
|
-inotin
|
Value is not in a collection of reference values - explicitly case-insensitive |
Returns if left object is not included in collection on the right - explicitly case-insensitive. |
|
-cnotin
|
If value is not in a collection of reference values - case-sensitive |
Returns if left object is not included in collection on the right - case-sensitive. |
Some examples are as follows:
# Initialization of variables
$numericValue = 42
$stringValue = 'Password.'
$hashtable = @('This', 'is', 'a', 'test', '!', 42)
# -eq
$numericValue -eq 42 # true
$numericValue -eq 24 # false
# -ne
$stringValue -ne 42 # true
$hashtable[5] -ne 42 # false
# -gt
$numericValue -gt 41 # false
$stringValue.Length -gt 5 # true
$hashtable.Count -gt 6 #false
# -ge
$numericValue -ge 41 # false
$stringValue.Length -ge 5 # true
$hashtable.Count -ge 6 #true
# -lt
$numericValue -lt 41 # true
$stringValue.Length -lt 5 # false
$hashtable.Count -lt 6 # false
# -le
$numericValue -le 41 # true
$stringValue.Length -le 5 # false
$hashtable.Count -le 6 # true
# -like
$stringValue -like '*Password.*' # true
$stringValue -like '42' # false
# -notlike
$stringValue -notlike '*Password.*' # false
$stringValue -notlike '42' # true
# -match
$stringValue -match 'Pass' # true
$Matches # Name = 0; Value = Pass
$hashtable -match 'is' # 'This', 'is'
# -notmatch
$hashtable -notmatch 'is' # 'a', 'test', !, 42
# -contains
$hashtable -contains 42 # true
$stringValue -contains 'Pass' # false
# contains validates collections and not strings - this is a typical error
# -notcontains
$hashtable -notcontains 4 # true
# not an exact match
# -in
42 -in $hashtable # true
'Pass' -in $stringValue # false
# in validates collections and not strings - this is a typical error
4 -in $hashtable # false
# not an exact match
# -notin
4 -notin $hashtable # true
# not an exact match, but negated
'is' -notin $hashtable # false
# an exact match - negated
As you can see in the example, most of the operators are straightforward. Just make sure that you understand that -in and -contains are dedicated to collections, and -match works with RegEx (Regular Expressions—a syntax to find and replace strings). In addition, -match will write its findings into the $Matches variable, which you can call after you have found matches.