PowerShell – How to use Equality operators?

PowerShell equality operators are used to compare values. These operators compare the values and return either True or False; when the given condition matches.

PowerShell provides below equality operators; as these are used for comparison, we can call them Comparison operators.

PowerShell Equality operators

All these equality operators takes 2 or more operands and compare the values; produce the comparison results. Results? Yes. These operators compares the values and returns True or False as the comparison result, if these applied on 2 operands. If more than 2 inputs are given, these operators returns the results with satisfied values. Let’s look at these with examples, below;

-eq and -ne operators

These operators verifies the equality check; whether the values of the given operands are equal (-eq) or not equal (-ne). These returns, True, if the comparison satisfies; otherwise, these returns the value False.

We can use these operators with numbers, arrays or collections and strings. When we use these operators with numbers; these simply compares the numbers and returns the result, True or False.

PS C:\> 1 -eq 1
True
PS C:\> 1 -ne 2
True
PS C:\> 12 -eq 20
False

When we use these operators with strings; these will compare the strings and returns the value True or False. The comparison is non-case sensitive; that means; these treats “Apple” and “apple” as the same strings. Capitals & Smalls, treats as equal;

PS C:\> "Buffer" -eq "buffer"
True
PS C:\> "True" -ne "true"
False

These operators allows; multiple values in left side and a single value in right side of the operator. If multiple values are given, each value must be separated by a comma (“,”). These will compare the right side value with the values in left side; and returns the matching entries. We can combine string & numbers when we use multiple values in the comparison;

PS C:\> 1, 2, “Hi!” -eq 1
1

PS C:\> (1, 2, "Hi!") -ne 1
2
Hi!

-gt and -ge operators

Greater than (-gt) and greater than or equal to (-ge) operators are used to compare the operands to identify which operand’s value is greater than or greater than or equal to, other operand’s value. These also takes 2 or more operands as inputs. Multiple operands must be separated by a comma (“,”); and these can be used only left side of the operator. Right side, always use the single operand. Otherwise, PowerShell throws an Error;

PS C:\> 1, 2 -gt 3, 4
Could not compare "1" to "3 4". Error: "Cannot convert the "System.Object[]" value of type "System.Object[]" to type "System.Int32"."
At line:1 char:1
+ 1, 2 -gt 3, 4
+ ~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (:) [], RuntimeException
    + FullyQualifiedErrorId : ComparisonFailure

We can use these operators with numbers & strings. String comparison is non-case sensitive. Here are some examples;

PS C:\> 1 -gt 2
False
PS C:\> 1, 2, 3 -gt 2
3
PS C:\> "hello!" -ge "hi!"
False
PS C:\> "PowerShell" -ge "powershell"
True
PS C:\> 10, "code" -gt 2
10
code

Observe that, we can combine numbers & strings in the comparison. Also, multiple values are separated by commas (“,”). When we use multiple values; the values which satisfies the condition returns as the result.

And we can not compare a number with a string; if we attempt, PowerShell will show the below Error;

PS C:\> 345 -gt "Hello, World!"
Cannot convert value "hello, World!" to type "System.Int32". Error: "Input string was not in a correct format."
At line:1 char:1
+ 345 -gt "hello, World!"
+ ~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidArgument: (:) [], RuntimeException
    + FullyQualifiedErrorId : InvalidCastFromStringToInteger

-lt and -le operators

Less than (-lt) and less than or equals to (-le) operators works similar to the above operators; and these will compare for the lesser value than the other value. Here are some examples;

PS C:\> 1, 2, 3 -lt 2
1
PS C:\> 0 -le 9
True
PS C:\> "False" -le "FALSE"
True

With these operators, we can not compare a number with a string; same as above.

These are the equality operators PowerShell provides for equality check.

[..] David