Minimum and Maximum Array Values

I determined something on Friday that I’m not sure I’ve needed before. I need to know which date in an array of dates, is the most recent—think the maximum value of the values in the array. Before we get to dates, let’s work with some simple-to-understand numeric values first.

In the below example, we’ll create a variable $Numbers and assign it five, out-of-order numerical values. Without much work, it’s easy to visually parse and determine the lowest value (the minimum value), and the highest value (the maximum value). One is the lowest and five is the highest.

$Numbers = 1,3,5,2,4
($Numbers | Measure-Object -Minimum).Minimum

1

($Numbers | Measure-Object -Maximum).Maximum

5

Let’s overwrite $Numbers with a different set of numbers—a larger set of random numbers. It’s not as easy to determine the smallest and largest of the numbers until we sort them.

$Numbers = Get-Random -Minimum 1 -Maximum 100 -Count 25
$Numbers

26
18
42
88
84
85
28
97
19
29
69
29
21
8
70
7
25
45
80
40
81
86
33
4
49

$Numbers | Sort-Object

4
7
8
18
19
21
25
26
28
29
29
33
40
42
45
49
69
70
80
81
84
85
86
88
97

Even though we can sort it, let’s return to Measure-Object and let it do the work for us. In the next two examples, you’ll notice that unlike the previous times I piped our array to Measure-Object, this time I didn’t only return the Minimum and Maximum properties. Instead, I returned all the properties in the object. They’re not all populated, but there’s a way to do that we’ll see soon enough.

$Numbers | Measure-Object -Minimum

Count             : 25
Average           :
Sum               :
Maximum           :
Minimum           : 4
StandardDeviation :
Property          :

$Numbers | Measure-Object -Maximum

Count             : 25
Average           :
Sum               :
Maximum           : 97
Minimum           :
StandardDeviation :
Property          :

Now, let’s try this with dates—both those that include times, and those that don’t. We’ll start by creating a $Date variable that contains five values. Once the values are assigned to our variable, we’ll display the contents of the array stored in our variable.

$Date = [datetime]'1/1/1975 02:05:48 PM',
[datetime]'2/2,1940',
[datetime]'1/1/1975 02:05:48 AM',
[datetime]'3/1/2022',
[datetime]'5/5/2080'
$Date

Wednesday, January 1, 1975 2:05:48 PM
Friday, February 2, 1940 12:00:00 AM
Wednesday, January 1, 1975 2:05:48 AM
Tuesday, March 1, 2022 12:00:00 AM
Sunday, May 5, 2080 12:00:00 AM

Let’s discuss the above dates before we move forward. We have one in 1940—the oldest—and one in 2080—the newest. These are the minimum and maximum, respectively. We have two on the same date in 1975. One happens at 2:05 in the morning and one at 2:05 in the afternoon. Which is the minimum and maximum of those values? You ought to be able to figure it out based on what you now know. Let’s work through some of the previous examples we did with our numerical array with this array. First, however, let’s ensure we’re working with an array—might as well.

$Date.GetType().BaseType.Name
Array

Ta-da. We’ll start by returning the minimum value, and then the maximum.

($Date | Measure-Object -Minimum).Minimum

Friday, February 2, 1940 12:00:00 AM

($Date | Measure-Object -Maximum).Maximum

Sunday, May 5, 2080 12:00:00 AM

Sure enough, 1940 is our minimum, and 2080 is our maximum. What happens when we sort the entire array? Will the two identical dates that include times sort properly? Let’s find out.

$Date | Sort-Object

Friday, February 2, 1940 12:00:00 AM
Wednesday, January 1, 1975 2:05:48 AM
Wednesday, January 1, 1975 2:05:48 PM
Tuesday, March 1, 2022 12:00:00 AM
Sunday, May 5, 2080 12:00:00 AM

They do. Now to put this to use! Perhaps I’ll be back with why I needed this. Before we wrap up though, let’s determine how to return more than just one property value at a time when using Measure-Object. Before that even, what happens when we don’t include any parameters?

$Numbers | Measure-Object

Count             : 25
Average           :
Sum               :
Maximum           :
Minimum           :
StandardDeviation :
Property          :

It only returns the Count property. We can use the AllStats parameter to return (just about) all of the properties at once.

$Numbers | Measure-Object -AllStats

Count             : 25
Average           : 46.52
Sum               : 1163
Maximum           : 97
Minimum           : 4
StandardDeviation : 29.7561198187308
Property          :

Until next time!