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Comparison Operators compares the value in PowerShell. There are four kinds of comparison operators that are used, namely equality, MATCH, containment and replace. In PowerShell, one of the essential comparison operators is –eq that is utilized inplace of “=” sign for declaring variables. Similarly, there are other operators like –ne for “not equal” , -gt ( greater than ) or –lt (less than).

PowerShell is securely incorporated into nearly all of Microsoft’s products. There are specific actions in POPULAR products like Microsoft 365 and Server 2016 that cannot be accomplished with a GUI and can solely be accomplished with PowerShell. It is 100% required for certain tasks, the capability to AUTOMATE with PowerShell makes comprehending it a worthwhile skill for numerous IT professionals. Once you begin to understand, all that can be accomplished with PowerShell, it unlocks a whole NEW set of capabilities. From fundamental automation to advanced scripting, PowerShell can deliver a LOT of opportunities for streamlining tasks and saving time. The above-mentioned question and answers will help ace the interview.

The CONCEPT of linking together commands with pipeline operator ( | ) is termed as a pipeline in PowerShell. That INDICATES the OUTCOME from the first command is further SENT down the pipeline as input to the second command for processing and the outcome of the second command is sent down to the pipeline as input to the third command and it goes on.

The functions of Get-ServiceStatus allow filtering of window services. PowerShell documents the services that are both ‘Running’, and ‘Stopped’ during scripting. By default, when Get-Service is operated without parameters, all the local computer's services are returned. You can control this cmdlet to obtain only certain services by selecting the service name or the display name of the services, or you can PIPE service objects to this cmdlet.

• EXAMPLE 1: Get all services on the computer
  This example fetches all of the services on the computer. It acts as THOUGH you TYPED Get-Service *. The default display displays the status, service name, and display name of each service.
  Get-Service
• Example 2: Get services that commence with a search string
  This example recovers services with service NAMES that start with WMI (Windows Management Instrumentation).
  Get-Service "wmi*"

The USAGE of Array in PowerShell is to EXECUTE a script against remote computers. To build an array, you have to construct a VARIABLE and assign the array. Arrays are defined by “@”SYMBOL, they are portrayed as hashtable but are not followed by curly braces.

To utilize an array in a program, you must call a variable to reference the array, and you can define the kind of array the variable can reference. 

MENTIONED below is the syntax for declaring an array variable:

Note − By default type of object of the array is System.Object. GetType() method returns the type of the array. Type can be passed.

Example:

The mentioned code snippets are examples of this syntax −

A hash table is also called the dictionary. It is a COLLECTION that LETS you ACCUMULATE data in a “key-value” pair association. The “key” and “value” can be of any data and length. To DISPLAY a hash table you will have to make USE of @ followed by curly braces.

The syntax of a hash table is as follows: 

When a VARIABLE is incorporated into double-quoted strings, then PowerShell TRANSFORMS the name of that variable via its value. Generally, this feature in PowerShell is emanated as variable interpolation. It PROVIDES a more readable, easier-to-read, and CONVENIENT syntax to create a formatted string.

The Get-COMMAND cmdlet ACQUIRES all commands that are performed on the computer, such as functions, CMDLETS, aliases, applications, filters, and scripts. Get-Command fetches the commands from PowerShell commands and MODULES that were imported from other SESSIONS. 

Example: Get commands in the current session

This command utilizes the ListImported parameter to obtain only the commands in the current session.

If you CONSTRUCT a WEB part with the help of VS 2010 then, you can deploy it UTILIZING cntrl+f5. To activate the web part component you can document a PowerShell script (.ps1) and run it after deployment.

Scripting debugging is an ESSENTIAL attribute to COMPREHEND how to use POWERSHELL. Concentrate on how scripting debugging can enhance your workflow and the entire project.

Scripting debugging is necessary as it permits IT professionals to QUICKLY scan the scripts, functions, expressions, and commands while executing. This allows us to DETERMINE possible errors, maintain model scripts and improve performance.

PowerShell pipeline is UTILIZED for combining TWO statements like when the output of a statement BECOMES the input of the second statement.

For example,

Command-1 | Command-2 | Command-3

In this example, the objects that Command-1 emits are sent to Command-2. Command-2 processes the objects and sends them to Command-3. Command-3 processes the objects and sends them down the pipeline. As there are no more COMMANDS in the pipeline, the results are displayed at the console.

PowerShell utilizes execution policies to regulate how it loads configuration files and runs scripts. Implementation of these policies only happens on Windows platforms. The PowerShell execution policies are mentioned below:

• AllSigned:
  • The scripts can run.
  • Needs that all scripts and configuration files be signed by a reliable publisher, which includes scripts that you compose on the local computer.
  • Encourages you before EXECUTING scripts from publishers that are still not categorized as untrusted or trusted.
  • Risks running signed, but VICIOUS, scripts.
• Bypass:
  • Nothing is stopped and there are no alerts or prompts generated.
  • The Bypass execution policy is created for configurations in which a PowerShell script is constructed into a larger application or for configurations in which PowerShell is the basis for a program that possesses its security model.
• Default:
  • Restricted for Windows CLIENTS.
  • RemoteSigned for Windows servers.
• RemoteSigned:
  • The default execution policy for the Windows system.
  • Scripts can run.
  • A digital SIGNATURE from an AUTHORIZED publisher is required on internet downloaded scripts and configuration files. It contains email and instant messaging programs.
  • It doesn't need digital signatures on scripts that are not downloaded from the internet and composed on the local computer.
  • It executes internet downloaded scripts that are not signed if the scripts are unblocked, like utilizing the Unblock-File cmdlet.
  • Risks executing unsigned scripts from sources except for the internet and signed scripts that could be malicious in nature.
• Restricted:
  • The default implementation policy for Windows client computers.
  • Allows individual commands, but does not permit scripts.
  • Stops operating all script files, including configuration files (.ps1xml), PowerShell profiles (.ps1), and module script files (.psm1) formatting
• Undefined:
  • There is no implementation policy specified in the current scope.
  • The execution policy is Restricted for Windows clients and RemoteSigned for Windows Server if the implementation policy in all scopes is Undefined.
• Unrestricted:
  • The default execution policy for non-Windows systems and cannot be modified.
  • Unsigned scripts can operate. There is a chance of running malicious scripts.
  • Alerts the customer before running scripts and configuration files that do not belong from the Local intranet zone.

• Parenthesis Brackets(): These brackets are utilized for REQUIRED arguments.
• Square Brackets[]: These sorts of brackets are used to specify the OPTIONAL items.
• Braces Brackets{}: These KINDS of brackets are utilized in BLOCKED statements.

The automatic variables are defined as those variables that save store state information for PowerShell. These variables will include the details of a customer and the system, default and runtime variables, and PowerShell settings. These variables can be designed and handled by Windows PowerShell.

A few of the very popular Automatic Variables are mentioned below:

• $: This variable INCLUDES the last token available in the last line that is received by the session.
• $?: This variable may include the completion status of the last operation. If the last operation succeeded, its value is TRUE and FALSE if it has failed.
• $^: It may include the first token of the last line obtained by the session.
• $Args: Includes a collection of the undeclared parameters or parameter values. These are handed over to a script, script block, or function. When you construct a function, you can display the parameters by making use of the param keyword or by incorporating a comma-separated list of parameters in parentheses just after the function name.
• $Error: This variable includes an array of error objects that represent the most recent errors. The current mistake is the first error object in the array ($Error[0]).
• $ForEach: This variable includes the ENUMERATOR (not the resulting values) of a ForEach loop. You can make use of the properties and processes of enumerators on the value of the $ForEach variable. This variable lives only while the ForEach loop is OPERATING; it gets deleted post the completion of the loop.
  $Home – This variable includes the full path of the customer’s home directory. This variable is the counterpart of the %homedrive%%homepath% environment variables, commonly known as C:\Users<UserName>.
• $OFS – $OFS is a remarkable variable that saves a string (Series of characters) that you wish to utilize as an output field separator. Employ this variable when you are transforming an array into a string. By default, the value of $OFS is ” “, but you can modify the value of $OFS in your session, by just typing $OFS=”<value>”. If you are anticipating the default value of ” ” in your MODULE, script, or configuration output, be mindful that the $OFS default value has not been modified anywhere in your code.

IT professionals make use of LOOPS when they require to complete a block of commands numerous times.

Example: An entry-controlled loop, a "while loop" runs commands consecutively as long as the provided condition is true. A bunch of IT professionals prefers to EMPLOY "while loops" rather than "for STATEMENTS" as the syntax is less complex."

The following example prints the values from 1 to 5 using the while loop:

1. PS C:\> while($count -le 5)
2. >> {
3. >> echo $count
4. >> $count +=1
5. >> }

Output:
1
2
3
4
5

In this instance, the condition ($count is less than equal to 5) is true while $count = 1, 2, 3, 4, 5. Every time through the loop, the value of a variable $count is incremented by 1 utilizing the (+=) arithmetic assignment operator. When $count EQUALS 6, the condition statement assesses to false, and the loop exits.

A variable is a unit of memory where values are stored. In PowerShell, variables are depicted by text strings that begin with a dollar sign ($), such as $a, $process, or $my_var. PowerShell variables are way more effective as those can be mapped to underlying CLASSES in the framework of .NET. PowerShell CONSIDERS variables as .NET objects, which implies they can save data and CONTROL data in numerous ways. Variable names in PowerShell start with a dollar sign and include a mix of numbers, letters, symbols, and spaces.

For example, $var="HELLO" SAVES the STRING HELLO in the $var variable. Variables can also possess various scopes, including global, local, script, private, and numbered scopes.