How a string is immutable

Question

Bcoz we can still modify a string
e.g."pine"+"apple"=pineapple
Here the string pine is modified....
So plz explain

Answer 1

the string is not modified but rather a new stri g is made and is referenced

1) x="hello"
2) y="world"
3) x=x+" "+y

what happens above is that on line 3 we assign a new concatanated string to x, destroying what was there before.
so we are not actually adding, but assigning something new constructed from the old

Answer 2

A String is an object of the string class.
your addition operator is only an abstraction to indicate the creation of a new String object that will hod the data resulting from the concatenation of two other objects.

Answer 3

Here pineapple is a new string.

eg. 2+3=5
here 2 is not modified into 5.