For c# developers that are staring out to learn Java, are there any big underlying differences between the two languages that should be pointed out?
Maybe some people may assume things to be the same, but there are some import aspects that shouldn't be overlooked? (or you can really screw up!)
Maybe in terms of OOP constructs, the way GC works, references, deployment related, etc.
No delegates or events - you have to use interfaces. Fortunately, you can create classes and interface implementations inline, so this isn't such a big deal
One thing that jumps out b/c it's on my interview list is that there is no "new" keyword analogue in Java for method hiding and there fore no compiler warning "you should put new here". Accidental method hiding when you meant to override leads to bugs.
(edit for example) Example, B derives from A (using C# syntax, Java behaves same way last I checked but does not emit compiler warning). Does A's foo get called, or B's foo? (A's gets called, probably surprising the dev who implemented B).
class A
{
public void foo() {code}
}
class B:A
{
public void foo() {code}
}
void SomeMethod()
{
A a = new B(); // variable's type is declared as A, but assigned to an object of B.
a.foo();
}