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How to use Enhanced for loop with 2D array

Davie Lin
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Joined: Aug 05, 2007
Posts: 294
Hi everyone, Has anyone try to use the Enhanced for loop with a 2D array?
How do you set it up? Much thanks for anyone providing hints
Garrett Rowe
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Joined: Jan 17, 2006
Posts: 1296
You need two enhanced for loops for your iteration. Try something like this:



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Amit Ghorpade
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Joined: Jun 06, 2007
Posts: 2716
    
    6

Why wait for someone else ?
Why dont you try it yourself ?
There is no other better way to learn it,I think.


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Davie Lin
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Joined: Aug 05, 2007
Posts: 294
Thanks for the ideas provided.
Amit Ghorpade
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Joined: Jun 06, 2007
Posts: 2716
    
    6

Looks like Garrett beat me on this by a few seconds
I had a similar piece of code on my mind as posted by Garrett.
But its the ranch policy to help people learn on their own so I refrained from posting it.
Campbell Ritchie
Sheriff

Joined: Oct 13, 2005
Posts: 39478
    
  28
There's no such things as a 2D array; in Java all arrays are one-dimensional. When you declare int[][] you are actually telling the JVM you want an array and its members are each arrays. Look for the short[][] example in Java Language Specification �10.2.
Amit Ghorpade
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Joined: Jun 06, 2007
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    6

You are right Campbell, there is no such thing as 2D array. But the term is widely used to mean an array whose individual elements are arrays.I think the reason behind this is the use of such arrays in matrices and 2D transforms.
Garrett Rowe
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Joined: Jan 17, 2006
Posts: 1296
Originally posted by Amit Ghorpade:
Looks like Garrett beat me on this by a few seconds
I had a similar piece of code on my mind as posted by Garrett.
But its the ranch policy to help people learn on their own so I refrained from posting it.


You're right of course. It's always a judgment call as to how much to actually hand to a poster, and how much to let them figure out on their own. In this case I made the judgment that the code was trivial enough that giving away the answer wasn't too harmful.
Campbell Ritchie
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Joined: Oct 13, 2005
Posts: 39478
    
  28
Originally posted by Amit Ghorpade:
You are right Campbell, there is no such thing as 2D array. But the term is widely used to mean an array whose individual elements are arrays.I think the reason behind this is the use of such arrays in matrices and 2D transforms.
Aren't there languages which really use 2D arrays? Then it might be that people forget Java is different in this respect. Note the Sun publications never say an array can be 2D.
Rob Spoor
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Joined: Oct 27, 2005
Posts: 19725
    
  20

Pascal / Delphi supports full multi-dimensional arrays, but also supports arrays of arrays.


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Campbell Ritchie
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Joined: Oct 13, 2005
Posts: 39478
    
  28
Thank you, Rob.
Amit Ghorpade
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Joined: Jun 06, 2007
Posts: 2716
    
    6

Originally posted by Garrett Rowe:


You're right of course. It's always a judgment call as to how much to actually hand to a poster, and how much to let them figure out on their own. In this case I made the judgment that the code was trivial enough that giving away the answer wasn't too harmful.


Hmm thats true
Campbell Ritchie
Sheriff

Joined: Oct 13, 2005
Posts: 39478
    
  28
As Garrett says, it is always a nice decision about how much to show a poster, but I think I would have done the same.
Amit Ghorpade
Bartender

Joined: Jun 06, 2007
Posts: 2716
    
    6

Even I would have done the same but after another post.
Anyways I think Garrett's view is justified.
 
 
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