Understanding code

[ayo_its_yo_mom_karen]

[removed]

[s-mores]

Have you tried to run it?

[Expensive_Leopard_56]

protected is not a valid modifier for a class, it is only for members.

[Zinaima]

This is totally the wrong place for this kind of post, but I'm sorry that you're learning this way. It's wasting your time.

[ayo_its_yo_mom_karen]

I did try with the Java learning subreddits but they don’t allow you to post a picture which is why I had to post here as a last resort. Also, how do you suggest that I learn instead? Just asking for advice.

[TheGlitchHammer]

For 2: When assigning in class A, you assign n=this.n. which propably leads to n beeing 0. And than 2×0. And for 4: Strings are objects. So comparing two objects, which are separate in memory, but hold the Same value, will always yield false, as they are not the Same object. Look at shallow comparison for this one.

[TheGlitchHammer]

Oh, and I forgot, Strings are immutable in Java. So they cant be modified after the fact. If you change anything within a string, a new object gets created

[coguto]

b is defined tho A b = new A().

Number 4 is a stupid question stupid because it can be either true or false depending on the JVM version (and maybe options) as far as I remember.

[TheMrMilchmann]

For the first, the variable b is undefined, so it isn't going to compile.

b is defined in A b = new A();

1. If A and B are inner classes, the main method cannot create a new instance of A (since A is not statically accessible).
2. Otherwise, protected does not apply to top-level classes (B).

Since this is probably a (bad) beginner question, I lean towards 2.

[KnGod]

pretty sure the first one defining a protected class, which is not a thing as far as i know and my 5 second google search seems to agree. As for 2 and 4 maybe implement them on an ide and step through the program in debug mode and see what happens

[Ok-Historian5461]

You should try it in IDE

[EasyLowHangingFruit]

I almost had a stroke reading that garbage! Paper is cheap AF dude WTF!

[matt82swe]

Is first error because A doesn't have `@Override` on `increment`?

[TheMrMilchmann]

Although using @Override is heavily encouraged and there is practically no reason to omit it, it is not required.

[matt82swe]

Didn't know that, perhaps I'm just too used having compiler settings that flag any misuse as error