I have 2 questions about the compareTo() method in the Interface video

in the method: compareTo (Object obj) { Treet other = (Treet) obj; if (equals(other)) { return 0; } int dateComp = mCreationDate.compareTo(other.mCreationDate); if (dateComp == 0) { return mDescription.compareToIgnorecase(other.mDescription); } return dateComp; }

question 1: how are you able to use a method (compareTo) inside it's very own implementation as was done to initialize dateComp variable. How was the compiler able to resolve that expression in other to assign a value to the dateComp variable? I'm confused because we are using a method inside it's very own definition.

question 2: I'm confused about the use of equals method in the if condition. what would the fully qualified version of that expression be other.equals(other)? I'm just confused by the expression: if (equals(other))

Thanks in advance!