String

[shruti patel]

string is immutable? right every one knows that, my
question is it advantage or disadvantage making string
immutable?

[Campbell Ritchie]

There is discussion of a similar subject in this recent thread.

[Arijit Daripa]

Originally posted by shruti patel:
string is immutable? right every one knows that, my
question is it advantage or disadvantage making string
immutable?

One of the advantages
Immutable objects behave like primitive datatypes a bit. Like....

    int i1 = 10;
    int i2 = i1;
    i2 = 20;              //i2 changes but i1 doesn't change here
 
    String s1 = new String("Original");
    String s2 = s1;
    s2 = s2.concat("1"); //s2 changes but s1 doesn't change here
 
    StringBuffer sB1 = new StringBuffer("Original");
    StringBuffer sB2 = sB1;
    sB2.delete(2,5);     //sB1 and sB2 both change here

So we can use String objects as we use the primitives, except some cases like argument passing etc

One of the Disadvantages
Whenever their(immutable objects') contents are tried to be changed, new objects are created and their references are assigned to the reference variable. Hence older objects are thrown floating in the HEAP,reducing usable memory size.
I am giving the keyboard a rest here, because it takes a long to disscuss it in depth. Follow Kathy Sierra & Bert Bates. It will help you the best.

[Amit Ghorpade]

And Shruti please make your subject more descriptive, so that readers get what you question is related to. Please read this for more information.