Win a copy of Design for the Mind this week in the Design forum!
  • Post Reply
  • Bookmark Topic Watch Topic
  • New Topic

mock question Wrapper issue

 
Youssef Ghazal
Greenhorn
Posts: 10
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hello

i try it one mock exam and i stopped in this question :


What will happen if you attempt to compile and run the following code?




1) 19 followed by 20
2) 19 followed by 11
3) Compile time error
4) 10 followed by 1



and i choose the second option ,and i confirmed my option with running the code and it showed "19 10"

but when i see them answer i was suprised they said a compile error will occurs

The wrapper classes cannot be used like primitives.

Depending on your compiler you will get an error that says someting like "Error: Can't convert java lang Integer". Wrapper classes have similar names to primitives but all start with upper case letters.

Thus in this case we have int as a primitive and Integer as a wrapper. The objectives do not specifically mention the wrapper classes but don't be surprised if they come up.




.i don't see why .
[ August 26, 2007: Message edited by: Youssef Ghazal ]
 
Ajay Divakaran
Greenhorn
Posts: 22
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
i got the o/p as
19 11
 
Jesper de Jong
Java Cowboy
Saloon Keeper
Posts: 15214
36
Android IntelliJ IDE Java Scala Spring
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Autoboxing (automatically converting primitive types to instances of wrapper classes) is a new feature of Java 5.

Was the mock exam you are doing for Java 1.4?
 
Youssef Ghazal
Greenhorn
Posts: 10
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
yes,
it's a java 4 version.
thanks
 
  • Post Reply
  • Bookmark Topic Watch Topic
  • New Topic