Im learning android and following a simple calculator app tu

I\'m learning android and following a simple calculator app tutorial.There\'s a snippet of code that I\'ve reproduced but I am getting an error on it and I\'m not sure why.The snippet of code is:

In my project, I am getting an error with R.menu.main. More specifically, the word menu in \'R.menu.main\' cannot be resolved or is not a field.

I don\'t see anything in the tutorial that I\'ve missed that would cause this. Can anyone give me some advise about how to solve it.

Thank you so much

Solution

I am not sure

add the menu.xml file inside /res/menu/ folder, this is an example: