Cannot find symbol: method findViewByID(int) [closed]

Been trying to figure out the problem for the last two hours. The solutions I have seen and tried are as follows:

• Invalidate caches/restart

• getView().findViewByID(R.id.button) or rootView.findViewById(R.id.button)

• Casing

        Button popUp = (Button) findViewByID(R.id.button);        
  

This is the video that I was following to create this.

Any help would be greatly appreciated, thank you.

Answer

Replace

Button popUp = (Button) findViewByID(R.id.button);

with this

Button popUp = (Button) findViewById(R.id.button); 

You are writing findViewByID it’s not allowed in android write findViewById