Sign Up

Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.

Have an account? Sign In

Have an account? Sign In Now

Sign In

Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.

Sign Up Here

Forgot Password?

Don't have account, Sign Up Here

Forgot Password

Lost your password? Please enter your email address. You will receive a link and will create a new password via email.

Have an account? Sign In Now

You must login to ask question.(5)

Forgot Password?

Need An Account, Sign Up Here

Please briefly explain why you feel this question should be reported.

Please briefly explain why you feel this answer should be reported.

Please briefly explain why you feel this user should be reported.

Sign InSign Up

ITtutoria

ITtutoria Logo ITtutoria Logo

ITtutoria Navigation

  • Python
  • Java
  • Reactjs
  • JavaScript
  • R
  • PySpark
  • MYSQL
  • Pandas
  • QA
  • C++
Ask A Question

Mobile menu

Close
Ask a Question
  • Home
  • Python
  • Science
  • Java
  • JavaScript
  • Reactjs
  • Nodejs
  • Tools
  • QA
Home/ Questions/Amazing solutions for the you cannot call a method on a null valued expression in powershell error
Next
Answered
Lilah Tremblay
  • 14
Lilah Tremblay
Asked: May 17, 20222022-05-17T11:29:23+00:00 2022-05-17T11:29:23+00:00In: Programs

Amazing solutions for the you cannot call a method on a null valued expression in powershell error

  • 14

. Advertisement .

..3..

. Advertisement .

..4..

I’m building a new program, but when I run it, an error pops up. The error displayed is as follows:

You cannot call a method on a null-valued expression.
 At C:\Users\xxx\Downloads\md5sum.ps1:6 char:29
 + $hash = [System.BitConverter]::ToString($md5.Compute ...
 + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 + CategoryInfo : InvalidOperation: (:) [], RuntimeException
 + FullyQualifiedErrorId : InvokeMethodOnNull

I have tried several workarounds, but they still do not get the desired results. If you have come across this situation and have a solution for the “you cannot call a method on a null valued expression in powershell” problem, pls let me know. Here is what I do:

$answer = Read-Host "File name and extension (ie; file.exe)"
 $someFilePath = "C:\Users\xxx\Downloads\$answer"
 
 If (Test-Path $someFilePath){
  $stream = [System.IO.File]::Open("$someFilePath",[System.IO.Filemode]::Open, [System.IO.FileAccess]::Read)
  $hash = [System.BitConverter]::ToString($md5.ComputeHash($stream))
  $hash
  $stream.Close()
  }
 Else{
 Write-Host "Sorry, file $answer doesn't seem to exist."
 }

Thanks!

♦ Suggestions of ITtutoria Team

This is because you have an undeclared variable (null). It is $md5. This must be declared in another place than the one you have commented on.

$md5 = new-object -TypeName System.Security.Cryptography.MD5CryptoServiceProvider

This error occurred because you tried to execute a method which does not exist.

PS C:\Users\Matt> $md5 | gm


 TypeName: System.Security.Cryptography.MD5CryptoServiceProvider

Name MemberType Definition 
---- ---------- ---------- 
Clear Method void Clear() 
ComputeHash Method byte[] ComputeHash(System.IO.Stream inputStream), byte[] ComputeHash(byte[] buffer), byte[] ComputeHash(byte[] buffer, int offset, ...

The null-valued expression was .ComputeHash() from $md5.ComputeHash(). The same effect could be achieved by typing gibberish.

PS C:\Users\Matt> $bagel.MakeMeABagel()
You cannot call a method on a null-valued expression.
At line:1 char:1
+ $bagel.MakeMeABagel()
+ ~~~~~~~~~~~~~~~~~~~~~
 + CategoryInfo : InvalidOperation: (:) [], RuntimeException
 + FullyQualifiedErrorId : InvokeMethodOnNull
cannot call a method on a null valued expression
  • 1 1 Answer
  • 453 Views
  • 0 Followers
  • 0
Answer
Share
  • Facebook
  • Report

1 Answer

  • Voted
  • Oldest
  • Recent
  • Random
  1. Best Answer
    lyytutoria Expert
    2022-06-04T00:33:53+00:00Added an answer on June 4, 2022 at 12:33 am

    The cause: You have an undeclared variable (null). It is $md5. This must be declared in another place than the one you have commented on.

    $md5 = new-object -TypeName System.Security.Cryptography.MD5CryptoServiceProvider

    This error occurred because you tried to execute a method which does not exist.

    PS C:\Users\Matt> $md5 | gm
    
    
    TypeName: System.Security.Cryptography.MD5CryptoServiceProvider
    
    Name MemberType Definition
    ---- ---------- ----------
    Clear Method void Clear()
    ComputeHash Method byte[] ComputeHash(System.IO.Stream inputStream), byte[] ComputeHash(byte[] buffer), byte[] ComputeHash(byte[] buffer, int offset, ...

    Solution: The null-valued expression was .ComputeHash() from $md5.ComputeHash(). The same effect could be achieved by typing gibberish.

    PS C:\Users\Matt> $bagel.MakeMeABagel()
    You cannot call a method on a null-valued expression.
    At line:1 char:1
    + $bagel.MakeMeABagel()
    + ~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo : InvalidOperation: (:) [], RuntimeException
    + FullyQualifiedErrorId : InvokeMethodOnNull
    
    
    • 18
    • Reply
    • Share
      Share
      • Share on Facebook
      • Share on Twitter
      • Share on LinkedIn
      • Share on WhatsApp
      • Report

Leave an answer
Cancel reply

You must login to add an answer.

Forgot Password?

Need An Account, Sign Up Here

Sidebar

Ask A Question
  • How to Split String by space in C++
  • How To Convert A Pandas DataFrame Column To A List
  • How to Replace Multiple Characters in A String in Python?
  • How To Remove Special Characters From String Python

Explore

  • Home
  • Tutorial

Footer

ITtutoria

ITtutoria

This website is user friendly and will facilitate transferring knowledge. It would be useful for a self-initiated learning process.

@ ITTutoria Co Ltd.

Tutorial

  • Home
  • Python
  • Science
  • Java
  • JavaScript
  • Reactjs
  • Nodejs
  • Tools
  • QA

Legal Stuff

  • About Us
  • Terms of Use
  • Privacy Policy
  • Contact Us

DMCA.com Protection Status

Help

  • Knowledge Base
  • Support

Follow

© 2022 Ittutoria. All Rights Reserved.

Insert/edit link

Enter the destination URL

Or link to existing content

    No search term specified. Showing recent items. Search or use up and down arrow keys to select an item.