Q1: What will be the output of the program?

String x = 'xyz';
x.toUpperCase(); /* Line 2 */
String y = x.replace('Y', 'y');
y = y + 'abc';
System.out.println(y);

ANS:A - abcXyZ

Line 2 creates a new String object with the value 'XYZ', but this new object is immediately lost because there is no reference to it. Line 3 creates a new String object referenced by y. This new String object has the value 'xyz' because there was no 'Y' in the String object referred to by x. Line 4 creates a new String object, appends 'abc' to the value 'xyz', and refers y to the result.