Objects Instantiated by JVM

Question

We know that Strings are objects in Java but we can write:
String a = "ab";
And we know that Arrays are also an object and we write:
int a[] = {1,2,3};
I've heard that compiler translate them to appropriate instanciation bytecode. It is correct?
It means thay are translated this way:
String a = new String ("ab"); ???
And for arrays, what class is instantiated?
Who has implemented this class? Where is it?

Answer 1

Example:
public void newString() {
    String foo = new String("ab");
// bytecode
Method void newString()
   0 new #2 <Class java.lang.String>
   3 dup
   4 ldc #3 <String "ab">
   6 invokespecial #4 <Method java.lang.String(java.lang.String)>
   9 astore_1
  10 return
public void newLiteral() {
    String foo = "ab";
// bytecode
Method void newLiteral()
   0 ldc #3 <String "ab">
   2 astore_1
   3 return