Often you may want to count the number of occurrences of each element in an array in PowerShell.
You can use the following syntax to do so:
$my_array | Group
This particular example will return the count of occurrences of each unique value in the array named $my_array.
You can also use the following syntax to return the count of occurrences, sorted in descending order by count:
$my_array | Group | Sort Count -Descending | Select Name, Count
The following example shows how to use each of these methods in practice.
Example: How to Count Occurrences of Each Element in Array in PowerShell
Suppose that we create the following array in PowerShell named $my_array:
$my_array = @(1, 1, 1, 4, 5, 5, 8, 8, 8, 9, 12)
We can use the following syntax to count the number of occurrences of each unique value in the array:
$my_array | Group
The following screenshot shows how to use this syntax in practice:
Notice that this returns an object with the following properties:
- Count: The count of occurrences of the element
- Name: The element name
- Group: A group that contains each occurrence of the element
We could also use the following syntax to return the count of occurrences of each element sorted in descending order:
$my_array | Group | Sort Count -Descending | Select Name, Count
The following screenshot shows how to use this syntax in practice:
From the output we can see:
- The value 8 occurs 3 times in the array.
- The value 1 occurs 3 times in the array.
- The value 5 occurs 2 times in the array.
And so on.
Feel free to leave out the parameter -Descending if you would instead like to display the count of occurrences in ascending order.
Related Tutorials
The following tutorials explain how to perform other common tasks in PowerShell:
PowerShell: How to Calculate the Average of an Array
PowerShell: How to Find Minimum and Maximum Values in Array
PowerShell: How to Compare Two Arrays
PowerShell: How to Find Duplicate Values in Array
