usage of (object) in assigning values for hashmap

Question

I saw a piece of java code using Hashmap as follows:

Map indata = new HashMap(12);
//load data
indata.put(“checking”, ((object) new  Double(1.0)));
indata.put(“PURPOSE”, ((object)"2”));

What confuse me is the two useages of "put" method, in which we have ((object) new Double(1.0)) and (object)"2". What do (object) function here? Any differences between ((object) new Double(1.0)) and (object)"2"?

Both casts to object. While retrieval it makes difference, you need to re-cast first one as Double and second one as String. — kosa
– kosa, Commented Jun 25, 2012 at 17:32

Tudor · Accepted Answer · 2012-06-25 17:37:35Z

2

It's a cast to Object (note that it's capitalized in Java).

It seems to be pointless here, as the code will compile fine without the cast (since the non-generic version of Map expects Object as the type of both key and value, so passing a String or a Double does not require explicit casting).

answered Jun 25, 2012 at 17:37

Tudor

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Comments

Ajinkya · Accepted Answer · 2012-06-25 17:36:55Z

1

Q: What do (object) function here?
A: Its just casting String and Double to Object.

Q: Any differences between ((object) new Double(1.0)) and (object)"2"?
A: NO

((object) new Double(1.0))  - casting Double into Object
((object)"2”) -  casting String into Object

EDIT:
Just realized from comments that it should be Object and not object

edited Jun 25, 2012 at 17:36

answered Jun 25, 2012 at 17:31

Ajinkya

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5 Comments

dantuch Over a year ago

the question is "for what?" ;)

Ajinkya Over a year ago

@dantuch: I have updated my answer to show what OP asked and what I understood (and answered). Please correct me if I am making any wrong assumptions.

dantuch Over a year ago

Yes, you have answered it without mistake, but that's not the point. When you see bad code, don't try to tell or guess what it does, but instead just simply point what's wrong with it. Here casting to Object is just plain stupid :)

dantuch Over a year ago

Anyway, +1 for your effort :)

Ajinkya Over a year ago

@dantuch: Now onward will try not to miss a bad code before looking for whats wrong with it :)

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