A Detailed Understanding of the Windows powershell function

June 2, 2023June 5, 2023 Edward 0 Comments powershell function

.When we wish to repeat a single line of code in a script, we utilize the powershell function. A function is a collection of commands with a name that the user specifies. We typically type the function name when executing any function. It makes it feasible to reuse PowerShell scripts and instructions in various situations.

Article Overview

A thorough explanation of powershell functions is given in this guide.

What does a powershell function mean?

A powershell function is a group of statements with input and output. It creates the instructions needed to invoke the code once or several times. Using functions in powershell makes dealing with repetitive code easier, which improves the code’s readability and usefulness.

Use positional parameters separated by spaces to invoke a function. Please be aware that while powershell call function, you need to send the arguments in order.

The types of categories

PowerShell functions are of two categories listed below:

Basic operation
A parameterized function (sometimes referred to as an advanced function)

Explained Function Types in Detail

Basic Functions

In PowerShell, there are two different types of functions. There are “basic” and “advanced” functions available. The simplest type of function is the “basic” function. They need the sophisticated built-in features that advanced functions have. The function statement is to construct or define it, followed by a pair of curly braces.

Syntax

The PowerShell basic function’s syntax is given here. This function has no built-in features.

The function keyword is used before the function’s name when initializing a function.
The pair of curly brackets contains the function’s body.

How to Write a Basic powershell function?

Launch PowerShell ISE and go to the scripting window to enter the following code. The sample code generates a straightforward function with an “echo” instruction.
It provides the script’s absolute path to run or execute it.
The output indicates that the function’s output was printed to the console.

Advanced Functions

Basic functions are functional, but you’ll frequently write complex functions. In addition to having all the capabilities of essential functions, advanced functions also include several built-in characteristics that basic functions do not. PowerShell, for instance, offers the idea of streams with names like Error, Verbose, Warning, etc. These streams are essential for providing consumers with accurate output presentation. Fundamental operations need to understand these streams naturally.

The syntax for a PowerShell advanced function is as follows:

Syntax

Examples of the syntax mentioned above are:

The term used to form a function is ‘function.’
When a preset list in the PowerShell library selects Verbs and Nouns, the function’s name represents as ‘Verb-Noun.’
The ‘param ()’ portion contains the user-declared arguments.
The initialization of variable values occurs in the ‘begin {}’ section.
The ‘process{}’ executes the variables and parameters initialized in the ‘param ()’ and ‘begin {}’ portions, respectively.
The ‘end {}’ segment finally clears the variables and parameters.

How to Write One?

A PowerShell advanced function built into the following lines of code adds the two integers.

The ‘Add-Num’ is initialized.
There are two integer parameters.
The ‘Add-Num’ function’s final line adds these variables and reports them using the ‘Write-Host’ cmdlet
After that, ‘Read-Host’ captures the user’s input.
The if-else condition then employs the ‘Add-Num’
The ‘if-else’ condition will compare the total of the integers; if it is less than 10, the if block will run instead of the else block.

The result demonstrates that the function (Add-Num) calculates the total and indicates that the returned sum is a number.

Conclusion

The powershell function has a specific name. A list of statements makes it up. Enclosing the function’s body in curly brackets begins with the function keyword, followed by a user-defined name. There are two sorts of PowerShell functions: basic functions and advanced functions. You have studied the fundamentals of basic and advanced features in this article.