Question

My code:

Object tempDifference;
Object testUser;
testUser = users.get(0);
it8 = difference_time.iterator();
it9 = users.iterator();
Object tempUser;
tempDifference = difference_time.get(0);

while (it9.hasNext()) {
  tempUser = it9.next();
  System.out.println(testUser+" "+tempUser);
  if (testUser.equals(tempUser)) {
    times.add(tempDifference);
    testUser = tempUser;
  } else {
    times.add(value);
    testUser = tempUser;
  }
  tempDifference = it8.next();
}

• Input is: 1 2 2

• Output is: 1 1

• I want output 1 2

Why is it the bad output 1 1 on beginning ?

Answer 1

Most iterators start Before the first element, so the first call to next() moves them to the first element, not the second.

So, if users = {1, 2}, and boiling it down somewhat:

//set test = 1, the first entry in the list
test = users.get(0); 
//get a new iterator, starting before the first element
it9 = users.iterator(); 
// move to first element (the next one), so temp == 1
temp = it9.next(); 
// print values "1 1"
System.out.println(test+" "+temp);