Question

1: import java.util.*;
2: class Test
3: {
4: public static void main(String[] args)
5: {
6: ArrayList<Object> list = new ArrayList<Object>();
7: list.add("First Element");
8: list.add(new Integer(12));
9: String str = (String) list.get(0);
10: String str2 = (String)list.get(1);
11: }
12: }

There is a run time error on which line number?

A) Line 9
B) Line 7
C) No errors
D) Line 8
E) Line 10

in Java

Answer 1

ANSWER:

The Answer is option E) line 10 .

The error message is "Exception in thread "main" java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.String at Test.main(Test.java:10).

That is we can't directly cast an integer to string.

Instead we use toString() method to get the casting from integer to string.

The corrected code is :

import java.util.*;
class Test
{
public static void main(String[] args)
{
ArrayList<Object> list = new ArrayList<Object>();
list.add("First Element");
list.add(new Integer(12));
String str = (String) list.get(0);
String str2 = list.get(1).toString();
}
} :

CODE ATTACHMENT:

1 2 3 4 5 6 7 8 9 10 11 12 Test.java import java.util.*; class Test { public static void main(String[] args) { ArrayList<object> list = new ArrayList<Object>(); list.add("First Element"); list.add(new Integer(12)); String str = (string) list.get(); String str2 = list.get(1).toString(); }.

OUTPUTS:

C:\Users \Documents>javac Test.java C:\Users \Documents>java Test Exception in thread "main" java.lang.ClassCastException: java.lang. Integer cannot be cast to java.lang.String at Test.main(Test.java:10) C:\Users \Documents>javac Test.java C:\Users \Documents>java Test C:\Users \Documents

Here the first execution rised runtime error that is cast. the error in Line 10.

I have corrected it and executed again so there are no errors in the second execution.

Please do comment for any queries.
Please like it.
Thank you.