Java - String and array references

Question

Just started to learn Java, and saw that both string and array are reference types. I don\'t understand the following issue:

    String a = \"a1\";
    String b          


        

Answer 1

First of all String is a immutable. Immutalbe means that you cannot change the object itself, but you can change the reference. Like in your case -

    String a = "a1"; // a is a reference variable and point to new object with value "a1"

    String b = "a2"; // b is a reference and point to new object with value "a2"

    a=b; // now a is referencing same object as b is referencing, a and b value is "a2"

    a = "rrr"; // at this time "rrr" is creating a new String object with value "rrr" and now a is pointing to this object.

So b is still point to "a2" and now a is pointing to new object "rrr". That's why both print different value.

    System.out.println(a);
    System.out.println(b);