The return specification of compareTo can afford without going to the reference

In Java without operator overload, the size comparison of objects is the .compareTo method, but can you tell which one returns positive, 0, or negative? I can't say And if you find a specification of what the return value is positive, 0, or negative, can you understand the conditional expression of the if statement at a glance while referring to it, or can you write it down smoothly and definitely? ⋯ It's so easy!

Let's make a table

Ah.

Putting a 0 to the ** right side of compareTo saves the inequality sign direction **. As a result, the return value specifications were set so that it would be the case.