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Integer : pass by value ?

 
Edward Chen
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I have tested pass-by-value and pass-by-reference , found the Integer will be passed by value ? why ? it is because Integer is wrapper class of primitive type ?

Thanks.

 
Paul Clapham
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No, it's much simpler than that. It's because all parameters are always passed by value in Java. You can read this Ranch campfire story which explains why that is.
 
Campbell Ritchie
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Lots of people get very confused about that. There are lots of explanations in this thread
 
Edward Chen
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Paul Clapham wrote:No, it's much simpler than that. It's because all parameters are always passed by value in Java. You can read this Ranch campfire story which explains why that is.


Thanks. Lots of discussions.

as said: "For references to objects, you pass a copy of the reference (the remote control)", reference is the address of the object, so we can say pass by object (reference), On the other side, reference is address, (0x1234), still is a value, so we can say we are passing a value. From this point of view, no any different.

Another question, Integer is an immutable class, like String ?

Thanks.
 
Ernest Friedman-Hill
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Edward Chen wrote:
Another question, Integer is an immutable class, like String ?


Yes. The Javadoc says so.
 
Campbell Ritchie
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Are you sure, Ernest; I can't find "immutable" in the documentation. It says "immutable" in BigInteger, however, for example.
 
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