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PowerShell

PowerShell : Continue Keyword

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Continue Keyword in PowerShell

One of the things that is a bit confusing for powershell beginner is the Continue statement. This is partially because it does not act like it might in some other languages. Next question will arise, then what does the Continue statement do in Windows PowerShell? the answer is it returns flow to the top of the innermost loop that is controlled by a While, For, or Foreach statement. 

Example:

In the following example, program flow returns to the top of the While loop if value of $myValue variable is equal to 6. As a result, all the numbers between 1 and 10 are displayed except for 5:

while ($myValue -lt 10)
{
$myValue += 1
if ($myValue -eq 6) {Continue}
Write-Host $myValue 
}

Output:

1
2
3
4
5
7
8
9
10

The Continue keyword supports labels. A label is a name you assign to a statement in a script, so the continue will skip in the current loop and execute form the  assigned label location. Let we discuss more about the labels in upcoming articles.

MVC

ASP.NET Core Real Power: Features And Benefits

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Introduction

ASP.NET Core 1.0 is not a continuation of ASP.NET 4.6. It is a whole new framework, a side-by-side project which happily lives alongside everything else we know. It is an actual re-write of the current ASP.NET 4.6 framework, but much smaller and a lot much more modular. There is no System. Web namespace anymore and everything which came with it.

It is the framework you want to use for web development with .NET. ASP.NET Core is a cross-platform, high-performance, open-source framework for building modern, cloud-based, Internet-connected applications. If you have any experience with MVC or Web API over the last few years, you will notice some familiar features. ASP.NET Core 1.0 is a 1.0 release that includes Web API and MVC but doesn’t have SignalR or Web Pages. It doesn’t yet support VB or F#.

If you have any experience with MVC or Web API over the last few years, you will notice some familiar features.This sequence of tutorials, will help you write an application using ASP.NET Core that can create, edit, and view data from a database.

Advantages of ASP.NET Core

Open Source:

ASP.NET Core is open source and available on GitHub,Which help to reduce the cost of hosting.NET application.

Platform Independent (Cross Platform Support):

ASP.NET Core 1.0 is a big fundamental change to the ASP.NET landscape and it is open source. ASP.NET Core is supported on Windows, Mac and Linux OSX

Built from scratch:

ASP.NET Core is not like an enhancement to ASP.NET 4.5 but it has been built from scratch. A lot of new features have been added to it and some of the existing features has been dropped also. To support Cross Platform and improve performance some existing features have been removed.

Modular Web Framework:

Asp.Net core everything is managed using nugget package, so it’s easy to upgrade new framework without releasing new .net framework version. In ASP.NET Core, a community can just release new NuGet package version and you will get latest changes by updating your packages. The .NET developer has the ability to pick and choose which ASP.NET features to include in their solutions. This opt-in model allows developers to be more deliberate with regard to which libraries are included in their projects

Dependency Injection:

Dependency injection is integrated into the framework for achieving loose coupling between objects and their collaborators.Third party products such as Autofac should still be available as an alternative to the build-in ASP.NET DI functionality.

Combination of MVC and WEB.API

In previous versions of ASP.NET, MVC and WEB.API were based on different versions of the framework ie., System.Web.Mvc and System.Web.Http/System.Net.Http, respectively. This has been removed and its been integrated with ASP.NET CORE 1.0 MVC 6. There is now a single set of objects within a single namespace (Microsoft.AspNet.Mvc). This standardized approach simplifies developing both MVC and WEB.API endpoints.

What do you think?

I hope you have basic about ASP .NET Core and its advantage . I would like to have feedback from my posts readers. Your valuable feedback, question, or comments about this article are always welcome.

ASP.NET Core

Introduction to ASP.NET Core

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Introduction

ASP.NET Core is the new web framework from Microsoft. It is the framework you want to use for web development with .NET. ASP.NET Core is a cross-platform, high-performance, open-source framework for building modern, cloud-based, Internet-connected applications. If you have any experience with MVC or Web API over the last few years, you will notice some familiar features.

ASP.NET Core 1.0 is a 1.0 release that includes Web API and MVC but doesn’t have SignalR or Web Pages.
It doesn’t yet support VB or F#.

What is ASP.NET Core

ASP.NET Core is an open source and cloud-optimized web framework for developing modern web applications that can be developed and run on across the many platforms like Windows, Linux and the Mac. It includes the MVC framework, which now combines the features of MVC and Web API into a single web programming framework.

What is New in ASP.NET Core?

ASP.NET Core ships entirely as NuGet packages. This allows you to optimize your application to include only the necessary NuGet packages rather than having all in application.

  • Open-source and community-focused.
  • A lightweight, high-performance, and modular HTTP request pipeline.
  • Ability to build and run on Windows, macOS, and Linux.
  • Ability to host on IIS, Nginx, Apache, Docker, or self-host in your own process.
  • ASP.NET Core apps can run on .NET Core or on the full .NET Framework.

What do you think?

I hope you have basic introduction and overview about ASP .NET Core. I would like to have feedback from my posts readers. Your valuable feedback, question, or comments about this article are always welcome.

 

PowerShell

Power Shell – Containment Operators

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Power Shell Containment Operators

The containment operators (-contains and -notcontains) are similar to the equal operators. However, the containment operators always return a Boolean value, even when the input is a collection. The conditional operator -Contains is similar to -eq, except it returns ‘True’ or ‘False’. -Contains is designed for situations where you wish to test for one particular item in a collection, array or a hash table.

Operators Description
-contains Returns true when reference value contained in a collection
-notcontains Returns true when reference value not contained in a collection
-in Returns true when test value contained in a collection
-notin Returns true when test value not contained in a collection

–contains

Always returns a Boolean value. Returns TRUE only when the test value exactly matches at least one of the reference values. When the test value is a collection, the Contains operator uses reference equality. It returns TRUE only when one of the reference values is the same instance of the test value object.

Syntax: <Reference-values> -contains <Test-value>

Example: 1

Contains checks each item between the commas

$Name = "John", "Ray Matt", "Anthony" 
$Name -Contains "Ray Matt"

OUTPUT

True

Example: 2

-Contains requires exact equality

$Name = "John", "Ray Matt", "Anthony" 
$Name -Contains "Ray"

OUTPUT

False

-notcontains

The negative -NotContains is not as useful as -NotMatch. However, from what we have already learned the syntax is predictable.

Syntax: <Reference-values> -notcontains <Test-value>

Example:

$Name = "John", "Ray Matt", "Anthony" 
$Name -notContains "Ray"

OUTPUT

True

-in Operator

In operator return the boolean value if the test value appears in a collection of reference values. Always return as Boolean value. Returns TRUE only when the test value exactly matches at least one of the reference values else it will returns FALSE.

Syntax: <Test-value> -in <Reference-values>

Example: 1

$Name = "John", "Ray Matt", "Anthony" 
"Ray" -in $Name

Output: 

False

Example: 2

$Name = "John", "Ray Matt", "Anthony" 
"Ray Matt" -in $Name

Output: 

True

-notin Operator

In operator return the boolean value if the test value appears in a collection of reference values. Always return as Boolean value. Returns TRUE only when the test value not a exactly matches at least one of the reference values else it will returns FALSE.

Syntax: <Test-value> -notin \<Reference-values>

Example: 1

$Name = "John", "Ray Matt", "Anthony" 
"Ray" -in $Name

Output: 

True

Example: 2

$Name = "John", "Ray Matt", "Anthony" 
"Ray Matt" -in $Name

Output: 

False
PowerShell

PowerShell : Do-While & Do-Until Loop

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Do-While & Do-Until Loop in PowerShell

Loops are an essential construct in any programming language as they enable a block of code to be repeatedly executed based on the condition. This can be useful for iterating through items in an object or repeatedly performing an operation. PowerShell supports involves setting a condition which either allows the loop to process as long as the condition is true or until it is met. 

  • The Do keyword works with the While keyword or the Until keyword to run the statements in a script block, up to the condition. The script block in a Do loop always runs at least once.
  • In a Do-While loop, the condition is evaluated after the script block has run. Then the while loop repeat the script until as long as the condition became false.
  • In a Do-Until loop always runs at least once before the condition is evaluated. However, the script block runs as long as the condition is false.

Do-While

Syntax : do {<statement list>} while (<condition>)

Example:

In below example, the loop will stop executing if condition became false that is if loop_index value reach 0 then condition became false.

$myArray = 1,2,3,0,4
do
{
$loop_index++;
}
while ($myArray[$loop_index] -ne 0)
$loop_index

Output:

3

Do-Until

Syntax : do {<statement list>} until (<condition>)

Example:

In below example, Do…Until loop is used when we want to repeat a set of statements as long as the condition is false.

$myArray = 1,2,3,0,4
do
{
$loop_index++;
}
until($myArray[$loop_index] -ne 0)
$loop_index

Output:

4

 

PowerShell

Power Shell – Type comparison

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What is comparison Operator?

Comparison operators let you specify conditions for comparing values and finding values that match specified patterns. To use a comparison operator, specify the values that you want to compare together with an operator that separates these values.

Type comparison

The type comparison operators (-is and -isnot) are used to determine if an object is a specific type.

Operators  Description
-is Returns true if both object are the same type
-isnot Returns true if the objects are not the same type

-is Operator

Syntax: <object> -is <type reference>

Example:

PS C:\>
$stringMsg1 = "dotnet-helpers"
$stringMsg2 = 100
$stringMsg1 -is $stringMsg2.GetType()
$stringMsg2 -is [int]

OUTPUT

False
True

-isnot Operator

Syntax: <object> -is <type reference>

Example:

PS C:\>
$stringMsg1 = "dotnet-helpers"
$stringMsg2 = 100
$stringMsg1 -isnot $stringMsg2.GetType()
$stringMsg2 -isnot [int]

OUTPUT

True
False
PowerShell

PowerShell – Replacement Operator

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Replacement Operator

PowerShell provides several options to help you replace text in a string with other text. The -replace operator replaces all or part of a value with the specified value using regular expressions. It replaces every occurrence of the exact string you specify with the exact replacement string that you provide. The -replaceoperator provides much more flexibility because its arguments are regular expressions that can match and replace complex patterns.

Operators  Description
-replace replace a string pattern


Syntax:

<input> <operator> <original> <substitute>

The syntax of the -replace operator is as follows, where the <original> placeholder represents the characters to be replaced, and the <substitute> placeholder represents the characters that going to replace.

Example:

PS C:\> 
$stringMsg = "Hi Welcome to dotnet-helpers.com"
$stringMsg -replace 'Hi' , "You are"

OUTPUT

You are Welcome to dotnet-helpers.com

By default, the -replace operator is case-insensitive. To make it case sensitive, you need to introduce ‘c’ as prefix like  -creplace. To make it explicitly case-insensitive, you need to prefix ‘it’ like -ireplace.

Example:

Here the output will be same text beacuse we maked a replace operator as case sensitive, so ‘HI’ does’t macth with the string.

PS C:\>
$stringMsg = "Hi Welcome to dotnet-helpers.com"
$stringMsg -creplace 'HI' , "You are"

OUTPUT

Hi Welcome to dotnet-helpers.com
PowerShell

PowerShell – Matching Operators

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-like and -notlike Operators

The like operators find elements that match or do not match a specified pattern using wildcard expressions.

How its handle single & Collection values?

If we input scalar value, comparison operators return a Boolean value. When the input is a collection of values, the comparison operators return any matching values. If there are no matches found in a collection then the comparison operators do not return anything.

The syntax is:

<string[]> -like <wildcard-expression>
<string[]> -notlike <wildcard-expression>

Example:1

PS C:\>

$singleValue = "Aadharsh"
$singleValue = $singleValue -like "Aadharsh"
Write-Host ""
Write-Host "Is varible contain 'Aadharsh' : " $singleValue

OUTPUT:

Is varible contain 'Aadharsh' : True

Example:2

$singleValue = "Aadharsh" , "Rakshu"
$singleValue = $singleValue -like "Aadharsh"
Write-Host ""
Write-Host "The matched value is : " $singleValue

OUTPUT:

The matched value is : Aadharsh

-match and -notmatch Operators

The match operators find elements that match or do not match a specified pattern using regular expressions. It search only in strings and they can’t search in arrays of integers or other objects.

The syntax:

<string[]> -match <regular-expression>
<string[]> -notmatch <regular-expression>

Example:1

PS C:\>

$singleValue = "Aadharsh"
$singleValue = $singleValue -match "Aadharsh"
Write-Host ""
Write-Host "Is variable contain 'Aadharsh' : " $singleValue

OUTPUT:

Is variable contain 'Aadharsh' : True

Example:2

$singleValue = "Aadharsh" , "Rakshu"
$singleValue = $singleValue -like "Aadharsh"
Write-Host ""
Write-Host "The matched value is : " $singleValue

OUTPUT:

The matched value is : Aadharsh

Note:

There is automatic variable called “matches” element which return the match elements. You can use $matches variable to get the matched value.

What is difference between -Like & -Match?

The most technical distinction is -Match is a regular expression, whereas -Like is just a wildcard comparison, a subset of -Match. If you need a wildcard to find this item’, then start with -Like. However, if you are sure that most of the letters in the value that you are looking for, then you are better you can go with -Match. -match operator is quite faster than -like operator.

PowerShell

PowerShell – Equal Operators

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Equal Operators:

The equal operators return a value of TRUE if its identical or return a value of FALSE if it is not identical. The entire pattern must match an entire value. By default, all comparison operators are case-insensitive. To make a comparison operator case-sensitive, precede the operator name with a “c”. For example, the case-sensitive version of -eq is -ceq. To make the case-insensitivity explicit, precede the operator with an “i”

Operators  Description
-eq equals
-ne not equals
-gt greater than
-ge greater than or equal
-lt less than
-le less than or equal

 

Example:

$userName = 'Rakshu'
$userName -eq 'rakshu'

$userName = 'Aadharsh'
$userName -ne 'rakshu'

$number1 = 100
$number1 -gt 50

$userName = 100
$userName -le 50

OUTPUT:

PowerShell

PowerShell Basics: Comparison Operators and Conditional Logic

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Comparison Operators and Conditional Logic

Comparison operators let you specify conditions for comparing values and finding values that match specified patterns. To use a comparison operator, specify the values that you want to compare together with an operator that separates these values.

Equality

Operators  Description
-eq equals
-ne not equals
-gt greater than
-ge greater than or equal
-lt less than
-le less than or equal



Containment 

Operators Description
-contains Returns true when reference value contained in a collection
-notcontains Returns true when reference value not contained in a collection
-in Returns true when test value contained in a collection
-notin Returns true when test value not contained in a collection

Matching

Operators Description
-like Returns true when string matches wildcard pattern
-notlike Returns true when string does not match wildcard pattern
-match Returns true when string matches regex pattern – $matches contains matching strings
-notmatch Returns true when string does not match regex pattern – $matches contains matching strings

Replacement

Operators  Description
-replace replace a string pattern

Type comparison

Operators  Description
-is Returns true if both object are the same type
-isnot Returns true if the objects are not the same type

By default, all comparison operators in powershell’s are case-insensitive. If we need to make a comparison operator case-sensitive, precede the operator name with a “c”. For example, the case-sensitive version of -eq is -ceq. If we need to the case-insensitivity explicit, precede the operator with an i. For example, the explicitly case-insensitive version of -eq is -ieq. Let we discuss more about the each set of operators in upcoming articles.