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Implicit promotion for constructor arguments

Andreas Sandberg
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Joined: Sep 14, 2005
Posts: 31
Hi Folks,

Can somebody explain why the code below compiles. Why does Main a = new Main(3) call the constructor that takes the float argument. How does JAVA handle implicit promotion for constructor arguments? Thanks!



"When the compilers not happy ain't nobody happy"
Seb Mathe
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Joined: Sep 28, 2005
Posts: 225
That's because an int can be automaticly converted to a float (or to a long, or a double)


Regards,<br />Seb<br /> <br />SCJP 1.4
Raghu Shree
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Joined: Mar 18, 2005
Posts: 143
Hi,

int value 3 is converted into float. So Math(3) is executed. For more information about casting refer this link.

http://www.javaranch.com/maha/Resources/CarlsNotes.txt


Raghu J<br />SCJP 1.4<br /> <br />The Wind and waters are always<br />on the side of the ablest navigators.<br /><a href="http://groups.yahoo.com/group/scjp_share" target="_blank" rel="nofollow">SCJP Group</a><br /><a href="http://groups.yahoo.com/group/JavaBeat_SCWCD" target="_blank" rel="nofollow">SCWCD Group</a>
A Kumar
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Joined: Jul 04, 2004
Posts: 978
Hi,

You can look at this way


byte->short->int->long->float->double

In fact here you can have char converts into int...apart from short...

char->int..



[ October 20, 2005: Message edited by: A Kumar ]

[ October 20, 2005: Message edited by: A Kumar ]
[ October 20, 2005: Message edited by: A Kumar ]
Henry Wong
author
Sheriff

Joined: Sep 28, 2004
Posts: 18117
    
  39

Try it with code tags...

Henry



Books: Java Threads, 3rd Edition, Jini in a Nutshell, and Java Gems (contributor)
A Kumar
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Joined: Jul 04, 2004
Posts: 978
Hi.

Thanks Henry...Thats what i was trying to convey...


Thomas Drew
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Joined: Sep 15, 2004
Posts: 47
Andreas
In your constructor Main(float i) you pass the float value for i in but you never assign it to anything. The this() call your constructor with no arguments which is always going to assign the value 3 to i.
 
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