Question

What is the output of the following code:

ArrayList list = new ArrayList();
String s1 = new String("Java");
String s2 = new String("Java");
list.add(s1);
list.add(s2);
System.out.println((list.get(0) == list.get(1)) + " " + (list.get(0)).equals(list.get(1)));


A. true false
B. false true
C. true true
D. false false

Answer 1

The code compares two String objects for reference and object equality, resulting in 'false' for reference equality and 'true' for object equality. The output is 'false true'.

Step-by-step explanation:

The code in question demonstrates the difference between reference equality and object equality in Java. When two separate String objects are created with the same content, using the new keyword, they are stored at different memory locations, resulting in different references. Therefore, the '==' operator, which checks for reference equality, will return false. On the other hand, the .equals() method is overridden in the String class to check the content of the strings. Since both objects have the same content, .equals() will return true.

Therefore, the output of the code will be:

false true

The correct answer is B. false true.