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static method.

 
Greenhorn
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public class Test {
public static void main(String args[]) {
StringBuffer a = new StringBuffer("One");
StringBuffer b = new StringBuffer("Two");
Test.swap(a,b);
System.out.println("a is "+ a +"\nb is " + b);
}
static void swap (StringBuffer a, StringBuffer b) {
a.append(" more");
b=a;
}
}
What will be the output?
Answer:
a. a is One
b is Two
b. a is One
b is One
c. a is One more
b is One more
d. a is One more
b is Two
e. a is One more
b is Two more
asnwer is d
i thougth answer is c
a.append(" more"); // now a is "One more"
b=a; // now b = a means b is also "One more"
Correct me where i am wrong ???
 
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append(" more"); // now a is "One more"
b=a; // now b = a means b is also "One more"
Correct me where i am wrong ???

YES (Inside the method )
NO (after returning from swap method execution)

For method calls Java passes the copy of the object's reference . This means when you change the value of the reference (a or b in this case) it does not change the original value of the object ref before this method is called.But if somehow you change the object's contents via these references inside the method IT CHANGES THE CONTENTS and the effect is there after retrning from the method. This explains why in this case the value of String a is changed to One more (because of the append method) and b's value is not changed (we just change the value of the copy of the reference).
regds
maha anna
[This message has been edited by maha anna (edited February 25, 2000).]
 
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