Java Programming - Java.lang Class - Discussion

There are only 3 objects will be created because.

In First line,

String x = new String("xyz");

"xyz" an object is created in memory which is referenced by x(reference variable).if u get the hasCode() of "Hello" and x both will be same because x is referenced to "xyz"

String y = "abc";

This line create one object "abc" which is referenced by y;

And finally when,
x = x + y;

A new object is created "xyzabc" which is referenced by x.
String class is an Immutable string so it is not changed a new object is created when concatenation is performed and is referenced by x.

"abc", "xyz", x, y and "xyzabc" total 5 objects will be created.

xyz will be lost as x now points to new concatenated string. Hence
5-1 = 4 objects.

There will be 3 objects created, Since the argument "xyz" is created, when its trying to create a new String object it will always check for the value in the "String Pool". If such a string object exists any newly created object of same value will be assigned to that object which contains the same value in string pool, it creates a new object in the string pool only if it doesn't exist.

As We Know String is Immutable, but here after concatenating it does not pointing the same ref in String pool, So its pointing new String in constant pool;.

Only 3 objects are created the first line creates only one object.

First line creates only reference x and one object and second line creates only another object. Third line do not create any object as it is again initialized to the x but strings are immutable.

So only 2 objects are created in all.

Please correct me if I'm wrong.

As eg.

If you write, String s= new String("hello");and check
if(s=="hello") then it will print false because == comapres references and as they are two different objects so line 1 in question will create 2 objects.

I am not able to understand the concept behind the answer. Kindly exlpain the solution in detail.

@Mmintz01,
Why not x point to xyz object (in your above e. G. ) directly ? isn't it waste of memory by creating 2 object considering xyz is never going to change by program. Kindly elaborate the advatage of this approach ?

The answer is simple :

java creates an object xyz in memory and then a x object which has the ingredients of object xyz. Then xyz is destryed (lost). So at the end we created 2 object but now we have one !