Question

Fill in each blank with the correct answer/output. Assume each statement happens in order and that one statement may affect the next statement. Hand trace this code instead of using your IDE. String s = "abcdefghijklmnop"; ArrayList r = new ArrayList(); r.add("abc"); r.add("cde"); r.set(1,"789"); r.add("xyz"); r.add("123"); Collections.sort(r); r.remove(2); The first index position in an array is __________. System.out.print( s.substring(0,1) ); // LINE 2 System.out.print( s.substring(2,3) ); // LINE 3 System.out.print( s.substring(5,6) ); // LINE 4 System.out.print( r.get(0) ); // LINE 5 System.out.print(r.get(0).substring(0,1)); // LINE 6 System.out.print( r.get(2) ); // LINE 7 System.out.print( r.indexOf("123")); // LINE 8 System.out.print( r.contains("abc")); // LINE 9 System.out.print( r.isEmpty()); // LINE 10 r.set(1, "\\\\"); System.out.print(r); // LINE 11 r.remove(1); System.out.print(r); // LINE 12 r.add("one"); System.out.print(r); // LINE 13 r.add(0,"five"); System.out.print(r); // LINE 14 r.clear(); System.out.print(r); // LINE 15 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.

Answer 1

String s = "abcdefghijklmnop";
ArrayList r = new ArrayList();
r.add("abc");
r.add("cde");
r.set(1,"789");
r.add("xyz");
r.add("123");
Collections.sort(r);
Value of the list r here is [123, 789, abc, xyz]

r.remove(2);
Value of the list r here is [123, 789, xyz]

System.out.print( s.substring(0,1) ); // LINE
This prints first character of String s
It prints a

System.out.print( s.substring(2,3) ); // LINE 3
This prints third character of String s
It prints c

System.out.print( s.substring(5,6) ); // LINE 4
This prints sixth character of String s
It prints f

System.out.print( r.get(0) ); // LINE 5
It prints first element in the list r
It prints 123

System.out.print(((String) r.get(0)).substring(0,1)); // LINE 6
It prints first character of first elment in the list
So, It prints 1

System.out.print( r.get(2) ); // LINE 7
It prints Second element in the list

System.out.print( r.indexOf("123")); // LINE 8
It prints index of "123" in list r

System.out.print( r.contains("abc")); // LINE 9
It prints true if "abc" in the list or It prints false

System.out.print( r.isEmpty()); // LINE 10
It prints true if the list is empty or It prints false

r.set(1, "\\\\"); System.out.print(r); // LINE 11
Sets the value at index to \\

r.remove(1);
removes value at index 1

System.out.print(r); // LINE 12
prints the list 

r.add("one");
appends value "one" to list

System.out.print(r);
prints the list

// LINE 13
r.add(0,"five");
adds "five" at start

System.out.print(r); // LINE 14
prints the list

r.clear();
clears the list 

System.out.print(r); // LINE 15
prints the list



The first index position in an array is 0

Output:
--------
a
c
f
123
1
xyz
0
false
false
[123, \\, xyz]
[123, xyz]
[123, xyz, one][five, 123, xyz, one]
[]