how to clear a variable which is set from command line by "set /p var1="

Question

In Windows batch files, I accept variable from user input by set /p var1=, after var1 is used, I don't know how to reset/clear its value.

If I don't reset/clear its value, when user meets set /p var1= again, and user enter directly. the previous input value will be still there. I don't want it, How to reset it for new user input?

Answer 1

To clear a variable, regardless how it was set:

set "var1="

Answer 2

rare issue, but you can try this:

set "var=%var*=%"