How do you check if environment variables are defined in windows batch scripting [closed]

Question

I am trying to create a batch file to check if the environment variables are defined or undefined and gives a certain output statement if it is or not. This is what I have and I can't seem to get the program to tell me that any argument is defined.

if not defined "%MyVar%" (
    echo MyVar is NOT defined
)

if defined "%MyVar%" (
    echo MyVar IS defined 
)

Answer 1

I think you mean to write:

if not defined MyVar (
  echo MyVar is NOT defined
)

and

if defined MyVar (
  echo MyVar IS defined 
)

This is because cmd.exe will expand the reference to the content of the variable if you enclose it within % characters. (You want to know if the variable itself is defined, not if a variable with the name of the content of that variable is defined.)

Note that environment variables (names within % characters) are different from replaceable parameters (%0, %1, etc.).

I would recommend switching to Windows PowerShell, because it has built-in parameter parsing features, variable scopes, real functions, and much, much more.