Variable declaration in loop

Question

check the code:
for (int i=0; i<10; i++) {
int tmp = 0;
i want to know whether the tmp variable would be created each time the loop repeats or just once the first time.
another simple question. check it;
Vector vect = new Vector();
vect = null;
declaring a variable (a vector actually) and after some lines vect is referenced to null. i want to know whether this line (referencing to null) would help the garbage collector to release the free memeory or not.

Answer 1

Or am I wrong? I thought that the variable onlygot
created once in the loop, but that it got assignedto
a new value each iteration. Why would it getcreated
each iteration? It's still in scope.I have no idea about compilers, but I'd guess that
it'll lose scope at the end on an iteration.
Otherwise, you wouldn't be able to re-declare it. All
declarations would have to happen before the loop, or
they'd be repeated. Then again, the compiler simply
might ignore the re-declaration, recognizing the loop.Now I have to say that I'm on very thin ice. I'm not used to read the output of javap, but I will give it a try:
class Test {
    public static void main(String[] args) throws Exception {
        for (int i=0; i<10; i++) {
            int tmp = 512;
            System.out.println(tmp);
}javap -c -l -s -classpath . Test.class gives
class Test extends java.lang.Object{
Test();
  Signature: ()V
  Code:
   0:   aload_0
   1:   invokespecial   #1; //Method java/lang/Object."<init>":()V
   4:   return
  LineNumberTable:
   line 1: 0
   line 8: 4
  LocalVariableTable:
   Start  Length  Slot  Name   Signature
   0      5      0    this       LTest;
public static void main(java.lang.String[]);
   throws java/lang/Exception
  Signature: ([Ljava/lang/String;)V
  Code:
   0:   iconst_0
   1:   istore_1
   2:   iload_1
   3:   bipush  10
   5:   if_icmpge       25
   8:   sipush  512
   11:  istore_2
   12:  getstatic       #2; //Field java/lang/System.out:Ljava/io/PrintStream;
   15:  iload_2
   16:  invokevirtual   #3; //Method java/io/PrintStream.println:(I)V
   19:  iinc    1, 1
   22:  goto    2
   25:  return
  LineNumberTable:
   line 3: 0
   line 4: 8
   line 5: 12
   line 3: 19
   line 7: 25
  LocalVariableTable:
   Start  Length  Slot  Name   Signature
   12      7      2    tmp       I
   2      23      1    i       I
   0      26      0    args       [Ljava/lang/String;
}Now I'm not really sure of what to look for. But I think the interesting part is the lines that says code 8 and 11. To me it looks like the value 512 is just stored in slot 2 in the LocalVariableTable. Hmm.. that raises a question. Does that indicate that the variable exists all the time?
/Kaj