This week's book giveaway is in the Clojure forum.
We're giving away four copies of Clojure in Action and have Amit Rathore and Francis Avila on-line!
See this thread for details.
Win a copy of Clojure in Action this week in the Clojure forum!
  • Post Reply
  • Bookmark Topic Watch Topic
  • New Topic

Wrappers -

 
Masood Alam
Greenhorn
Posts: 8
  • 0
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Greetings,

In the below code //Line 1 results in "true" and the //Line results in "false"

Could someone please explain... its seems to be similar to "String Pool"

/**************************CODE*************************************/

class TestIntegers{

public static void main(String[] args){

Byte b1= 5;
Byte b2 = 5;
Byte b3 = new Byte("10");
Byte b4 = new Byte("10");
System.out.println("First Style " + (b1 == b2)); //Line 1
System.out.println("Second Style " + (b3 == b4)); // Line 2

}

}
 
Ulf Dittmer
Rancher
Pie
Posts: 42966
73
  • 0
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
b1 and b2 are created using auto-boxing, which doesn't employ "new Byte(...)", but rather Byte.valueOf(...). The difference is that valueOf doesn't create a new object - it reuses an existing one. Hence the two objects are identical.
 
Jared Folino
Greenhorn
Posts: 25
  • 0
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Just remember that it is only for wrappers between -128 and 127
 
kaushik vira
Ranch Hand
Posts: 102
  • 0
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
hello Masood,

I think you are using jdk 1.5 for you compiling code.. try this code in 1.4 it wan`t allow you to compile this code...

what is going on here due to new feature added in 1.5 is auto bouncing.. so go thorough it..

And remember you are preparing for scjp 1.4 or scjp 1.5.. your ans vary based on this..

in 1.4 it give you compilation error...
in 1.5 it give wan`t give you any error and will work fine...
 
I agree. Here's the link: http://aspose.com/file-tools
  • Post Reply
  • Bookmark Topic Watch Topic
  • New Topic