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StringBuffer and String Confused!!

 
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I wrote this piece of code


Till line no.2 i understood the output, but line no.3 output i didnt understand how the output is rattbFoar.
pls someone explain me
 
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Hi Asha,




From where you found output. I wrote code I got output "atto". That was I also answered.


It looks like you are taking "Java.Inquisition" mock exam. I am also taking that only. I have just posted my doubt about "Drag & Drop" question. If you know can you please help me. I am little stuck over there. I appreciate your help.
 
asha ganapathy
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Hi Dolly,

I got the output by executing on my machine..yes even i am using the same mock exam.Even i thought the output should have been "atto".
But after executing this code i found that
String s7 = sb.toString().substring(1, 5);
gives magically this output "rattbFoar", i wanted to know how toString() function performs.

Asha
 
asha ganapathy
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Yes Dolly if i know the answer to your question i can surely help you out
 
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Originally posted by asha ganapathy:
Hi Dolly,

I got the output by executing on my machine..yes even i am using the same mock exam.Even i thought the output should have been "atto".
But after executing this code i found that
String s7 = sb.toString().substring(1, 5);
gives magically this output "rattbFoar", i wanted to know how toString() function performs.

Asha


Hello Asha, are you really sure that you got "rattbFoar"? Because I tried running it and got "atto". If you look at the call: substring(1, 5) will give you a string of 4 characters. So the output can never be "rattbFoar".

So check your code - probably your test program is not exactly the same as the code above, or you have an old version of a class file somewhere, etc.
 
dolly shah
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i wanted to know how toString() function performs.



toString()converts StringBuilder or StringBuffer in String.
 
asha ganapathy
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oh i guess it was running with an older version of .class file
Thanks a lot
 
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Originally posted by asha ganapathy:
oh i guess it was running with an older version of .class file



I doubt that would cause a failure as described.



javac 1.5.0_12

java version "1.5.0_12"

In general, toString often constructs a new String reference.

But not always:

[asha ganapathy:] ... wanted to know how toString() function performs.



Try not to guess unless you are investigating borderline conditions or doing intentionally exploratory work.



re:


One more clarification required..what is equals() method used for?
s1.equals(s2) -> checks if both Strings have same value or not?
please correct me if i am wrong.


posted Sunday, August 05, 2007 8:07 PM in Java (beginner) Strings
t = 023603 (topic)
f=33 (forum)

In general, == should be used to test for equality of primitives,

use dot equals for everything else .... there is no substitute for testing.

[ August 30, 2007: Message edited by: Nicholas Jordan ]
 
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