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Iterator Worksheet

Last updated almost 2 years ago

4 questions

1

Question 1

1.

What is output by the code at right?

ArrayList<Integer> x = new ArrayList<Integer>();
x.add(11);
x.add(9);
Iterator<Integer> it = x.iterator();
System.out.println(it.next());
System.out.println(it.next());

1

1

1

Question 2

2.

What is output by the code at right?

ArrayList<Integer> w = new ArrayList<Integer>();
w.add(4);
w.add(6);
w.add(8);
Iterator<Integer> iter = w.iterator();
while(iter.hasNext()){
System.out.println(iter.next());
iter.remove();
}
System.out.println(w);

Question 3

3.

What is output by the code at right?

ArrayList<Integer> z;
z = new ArrayList<Integer>();
z.add(3);
z.add(7);
z.add(3);
z.add(7);
z.add(9);
z.add(5);
System.out.println(z);
Iterator<Integer> itera = z.iterator();
while(itera.hasNext()){
if(itera.next().compareTo(7)==0)
itera.remove();
}
System.out.println(z);

Question 4

4.

What is output by the code at right?

ArrayList<Integer> a = new ArrayList<Integer>();
a.add(5);
a.add(6);
a.add(9);
a.add(7);
a.add(2);
ListIterator<Integer> iterator = a.listIterator();
iterator.next();
iterator.set(1);
iterator.next();
iterator.set(4);
iterator.previous();
iterator.remove();
iterator.previous();
iterator.set(0);
System.out.println(a);