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immutable?????????

 
Ranch Hand
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we know that strings are immutable.

then how come in the following code s1 prints 3

public class Test
{

public static void main (String[] args)
{
String s1 = "1";
String s2 = "2";
String s3 = s1;
s1="3";
System.out.println(s1+s2+s3);/////
}
}
 
Greenhorn
Posts: 4
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Strings are immutable,but what we're talking about here is the String object. s1 is a reference,and can obviously point to any String object.
 
lowercase baba
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What you are doing here is telling the JVM to create a brand new string "3", and change s3 to refer to it. the original string that s3 USED to refer to hasn't changed... if you print s1, it'll still print "1".

in other words, you can chage what string a reference points to, you can create new string, but you CAN'T change an old string.
 
Greenhorn
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public class TimDig extends TimDigSuper{
//String device = "Mobile.device";
public static void main(String[] args) {
String s1 = new String("D");
String s2 = "2";
String s3 = s1;
s1.toLowerCase();
System.out.println(s1+s2+s3);/////
}


}
Try this and see ur doubt will be cleared as what immuteable means.
cheers,
Santu.
 
Ranch Hand
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Hi there
Just a doubt.
Does the output for the above code is "321"..
regards
Balaji.S
 
Greenhorn
Posts: 29
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try run it... but yes it gives 321
 
Greenhorn
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Ya the output is 321 but what is being asked for is just s1, which is 3 only
 
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