How to Convert String to Integer in PowerShell

1. Use [int] to Convert String to Integer in PowerShell
2. Use [System.Int32] to Convert String to Integer in PowerShell
3. Define the Data Type of a Variable to Convert String to Integer in PowerShell
4. Conclusion

In PowerShell, knowing how to convert strings to integers is a valuable skill. This tutorial will teach you to convert strings to integers in PowerShell.

We will look into the technique of using [int] and [System.Int32] to perform this conversion, allowing you to easily modify your data.

Use [int] to Convert String to Integer in PowerShell

In PowerShell, we can use [int] to convert a string to an integer. This is called type casting or type conversion.

The following syntax is a simple assignment statement in PowerShell, where we are converting a string to an integer and assigning the result to the variable $integerVariable.

Syntax:

$integerVariable = [int]$stringVariable

Parameters:

• $integerVariable: This is a variable that will hold the integer value after conversion.
• [int]: This is used for type casting the value of $stringVariable to an integer.
• $stringVariable: This is another variable or expression containing a string that you want to convert to an integer.

Let us consider that we have a variable $a as shown below.

$a = 123

The data type of $a is an integer.

$a.GetType().Name

Output:

Int32

But when we enclose the value with " ", the data type will become string.

$b = "123"
$b.GetType().Name

Output:

String

To convert the string ($b = "123") data type to an integer, we can use [int] as shown below.

$b = $b -as [int]
$b.GetType().Name

In the code above, we start with the variable $b. The current value and data type of $b are unknown to us at this point, but we want to ensure it is treated as an integer.

Next, the $b -as [int], we use the -as operator for safe type casting. It attempts to convert the value of $b to the specified type [int].

If it can be converted, the result is assigned back to $b. If not, $b remains unchanged.

In the next line, we use $b.GetType().Name to determine the data type of the variable $b after the type casting operation.

Now, let’s go through what happens with a variable $b having a specific value and type:

• If $b initially contains an integer (e.g., $b = 42), the code will not change its type, and the output will be Int32.

• If $b initially contains a string that can be successfully converted to an integer (e.g., $b = "123"), the code will change its type to an integer, and the output will be Int32.

• If $b initially contains a string that cannot be converted to an integer (e.g., $b = "hello"), the code will not change its type, and the output will be the type of the original value, which, in this case, is a string so that the output would be String.

Output:

Int32

Given the output Int32, it implies that the initial value of the variable $b (before this code snippet) was either an integer or a string that could be successfully converted to an integer.

Use [System.Int32] to Convert String to Integer in PowerShell

The [System.Int32] is a form of typecasting that converts a string to an integer in PowerShell, which explicitly tells PowerShell to treat a variable or expression as an Int32 data type.

In the syntax, we convert a string in $stringValue to an integer, storing the result in $intValue. This is done using the [System.Int32] syntax to specify the desired data type, making $stringValue ready for numeric operations.

Syntax:

$intValue = [System.Int32]$stringValue

Parameters:

• $intValue: This variable stores the integer value after the conversion.
• [System.Int32]: This denotes the desired data type, specifying that the value should be treated as a 32-bit integer.
• $stringValue: This contains the value to be converted, typically a string with a numeric value.

Let’s give an example.

$stringValue = "456"
$intValue = [System.Int32]$stringValue
$intValue.GetType().Name

In the code, we begin by setting a string variable named $stringValue to the value "456". Then, we proceed to convert this string into an integer using [System.Int32] and store the result in another variable, $intValue.

After this conversion, we inquire about the data type of the variable $intValue using $intValue.GetType().Name.

Output:

Int32

The output tells us that the variable $intValue contains an integer, specifically a 32-bit integer, as indicated by Int32, which is the name of the data type.

Define the Data Type of a Variable to Convert String to Integer in PowerShell

PowerShell can detect the data type of a variable on its own.

We don’t need to be specific about the data type and declare a variable. But, we can define the data type of a variable before it so that we can force the data type.

Let’s give an example.

[int]$c = "456"
$c.GetType().Name

In the code above, we declare the variable and initialize it like this: [int]$c = "456". This line tells PowerShell to explicitly cast the string "456" to an integer, and the result is then stored in the variable $c.

Next, we want to know the data type of the variable $c, so we use $c.GetType().Name. This is our way of checking whether the typecasting was successful.

Output:

Int32

The output above is Int32, indicating that the string "456" has been converted into an integer. But, if you try to force an integer data type to a string value, you will get an error like in the following code example.

[int]$data = "storage"
$c.GetType().Name

In the code above, we start by declaring a variable named $data and assigning the string value "storage" to it. The next line, [int]$data, represents an attempt to forcefully cast the string "storage" to an integer data type.

Now, we’re going to check the data type of the variable $data using $data.GetType().Name.

Output:

Cannot convert value "storage" to type "System.Int32". Error: "Input string was not in a correct format."
At line:1 char:1
+ [int]$data = "storage"
+ ~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : MetadataError: (:) [], ArgumentTransformationMetadataException
    + FullyQualifiedErrorId : RuntimeException

We try to cast it as an integer using [int]. However, since the string "storage" cannot be converted to an integer, PowerShell does not change the type of the variable and returns an error message "Input string was not in a correct format.".

Conclusion

In this article, we’ve learned to convert strings into integers using [int] and [System.Int32]. Now, we can easily transition between text to numbers in PowerShell.

By controlling variable types, you gain accuracy and versatility in your scripts.