Tuesday, 31 January 2017

PowerShell Array : Initialize, Add and Remove Items

Array holds a list of data items. The Powershell array items can be the same type or different types.

Create or Initialize an empty array :

The following syntax just creates an empty array object.
$myArray = @()

Create array with items :

We can easily create predefined Array by just setting comma separated elements.
$myArray = "A","B","Hello","World"
Using explicit syntax:
$myArray = @(1,2,3,4,5)

Add values to an array :

We can add items to an array object by using the + operator.
$myArray = @(1,2,3,4,5)
$myArray = $myArray + 6
You can simplify the add operation by using assignment operator.
$myArray += 6
You can also add another array object using + operator.
$myArray += $secondArray

Read the contents of an array :

We need to specify index number to retrieve an element from array, The Powershell array elements starting at 0th index.

Display all the elements in an array:
$myArray
This command returns the first element in an array:
$myArray[0]
This command displays the 2nd,5th,8th elements
$myArray[1,4,7]
Return the range of elements (4th element to the 8th element):
$myArray[3..7]
Return the last element in an array:
$myArray[-1]

Contains check in array :

If you want to find an array contains a certain value, you don’t have to iterate through elements to compare the values with search term. Instead, you can apply filter with various comparison operators directly to the array.
$myArray = "A","B","C","Hello","World"
This command would check and return the array elements contains the string "Worl".
$myArray -like "*Worl*"
This command would check if the first three array elements contains the string "B" and return values.
$myArray[0..2] -like "*B*"

Set or Update array values :

Use the assignment operator (=) to change or update values in an array.
$myArray[2]=23

Sort an elements :

You can simply sort the elements by using Sort operator.
$myArray = $myArray | Sort

Delete an array and elements :

You can easily delete an entire array object by setting its value as null
$myArray = $null
But Arrays are fixed-size, so, you can not easily remove values at different indexes. For this need, you need to use System.Array or System.Collections.Generic.List.

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