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ArrayList sorting

Jeansonne Pierre
Greenhorn

Joined: Sep 11, 2011
Posts: 12


this code compiled succeed, but come out with warning message as below

Note: .\Sorting.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.


which part of code should i modify or improve to remove the warning messages?

Please help.
Thanks in advance
Winston Gutkowski
Bartender

Joined: Mar 17, 2011
Posts: 8049
    
  22

Jeansonne Pierre wrote:which part of code should i modify or improve to remove the warning messages?

Add a type to your Arraylist, viz:
ArrayList<Double> arrayList = new ArrayList<Double>();

Winston

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Jeansonne Pierre
Greenhorn

Joined: Sep 11, 2011
Posts: 12
Thanks Winston Gutkowski,

the warning messages gone and it succeed.

anyway, I'm wondering why it is

instead of ?

as the method argument received is in double primitive type.
Winston Gutkowski
Bartender

Joined: Mar 17, 2011
Posts: 8049
    
  22

Jeansonne Pierre wrote:anyway, I'm wondering why it is

as the method argument received is in double primitive type.

Because types must be objects. An ArrayList can't hold doubles.

Winston
 
It is sorta covered in the JavaRanch Style Guide.
 
subject: ArrayList sorting