PowerShell: Convert String to Int

PowerShell belongs to a dynamic, not strongly typed language class. This means you don’t need to declare variables and set specific data types before using them. When you create a variable, you don’t need to specify its type: PowerShell will try to figure it out on its own.

How to Convert String to Integer in PowerShell?

When performing various actions on a variable, PowerShell can automatically determine the variable type, but this doesn’t always work well and correctly. Recently, we faced a problem: the PowerShell cmdlet returns a number in a variable of String type. As a result, we cannot compare it with another variable of type Integer. In this article, we will look at how to set the type of a PowerShell variable and convert a string value to an integer.

For example, let’s create a simple variable and check its type using the GetType () method:

$a = 1

$a.GetType()

PowerShell automatically assigned the type Int32 (Integer) to this variable.

$b = "1"

$b.GetType()

If you set the value of a variable in quotation marks, PowerShell assumes it’s a string and returns a String type for it.

You can specify both the type of the variable and the type of the value. The following commands will create a variable containing a numeric value:

[int]$number = 1

$number.GetType().FullName

$number1 = [int]1

$number1.GetType().FullName

Hint. Other popular data types in PowerShell:

[string]
[char] — ASCII character code
[bool] — “True” or “False”;
[int] — 32-bit number;
[long] — 64-bit number;
[decimal] — a floating point number of 128 bits and a d at the end;
[double] — 8 bit floating point number;
[single] — 32 bit floating point number;
[DateTime] — Powershell datatype storing date and time;
[array] — PowerShell array;
[hashtable] — hash table;
[pscustomonject] — array of type key and value.

If you try to assign a string value to a numeric variable or try to perform other numeric operation, you get an error:

[int]$number = 'Test'

Cannot convert value “Test” to type “System.Int32”. Error: “Input string was not in a correct format.” ArgumentTransformationMetadataException

Let’s say you have a variable containing a string (type System.String):

$stringN = “777” 
$stringN.GetType().FullName

The easiest way to convert a value to System.Int32 is to assign its value to a new variable with a declared data type:

$integerN = [int]$stringN

Or:

$integerN = [int]::Parse($stringN)

You can also use the -as operator:

$integerN1 = $stringN -as[int]

Or convert the data type using the ToInt32 method of the Convert class (the second argument of the Toint32 class specifies the number system):

$integerN2 =[convert]::ToInt32($stringN)

Any of these methods converts the String variable to System.Int32 type.

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Cyril Kardashevsky

I enjoy technology and developing websites. Since 2012 I'm running a few of my own websites, and share useful content on gadgets, PC administration and website promotion.

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