PowerShell: Two Interview Questions

 During a recent interview I was asked the following questions.

How do you remove duplicates from an array?

My answer was to perform a Select-Object on the array as there must be an command-line option to return only unique values. The Select-Object cmdlet behaves like C#'s LINQ and removing duplicates is something I would do in LINQ.

The answer is Select-Object -Unique:

[int[]] $arrayWithDuplicates = 1, 2, 3, 3, 3, 2, 1, 1, 3, 1, 2, 3

[int[]] $arrayWithUniqueValues = 

    $arrayWithDuplicates | Select-Object -Unique

$arrayWithUniqueValues -join ' '

The output of the above script is:

1 2 3

How do you read the first five lines of a file?

My answer was to perform a Get-Content on the file as there must be an command-line option to return only finite number of lines from the file. 

The answer is Get-Content <filename> -TotalCount 5 where an example is as follows:

Get-Content 'InterviewQuestions.ps1' -TotalCount 5