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Boxing n Auto boxing-marcus green

shilpa Reddy
Ranch Hand

Joined: Jul 26, 2006
Posts: 42
if anyone can pass on the link where boxing and auto boxing is explained clearly......if there are any tips on this by marcus wuld be even more having k&&b....i need some other link....also about regex classes and pattern matching....thanks in advance.....
Marcus Green
arch rival

Joined: Sep 14, 1999
Posts: 2813

autoboxing addresses the code needed to get around the difference between primitives and the Wrapper classes used to store primitives. In the past it was necessary to call a method of the wrapper class to extract the primitive value. So the following code is typical.

With Java 1.5 it is possible to write

Note how the instance of the integer class is assigned directly to the int primitive without any need for conversion. Note that if you are using mock exams from earlier versions of Java you may find that the behaviour of JDK1.5 means the answer is �incorrect�, but that it is simply because of the effect of autoboxing.


SCWCD: Online Course, 50,000+ words and 200+ questions
shilpa Reddy
Ranch Hand

Joined: Jul 26, 2006
Posts: 42
thanks for your explanation.......i have another doubt in formatting

int i1 = -123;
int i2 = 12345;

System.out.printf(">%0,7d< \n", i2);
System.out.format(">%+-7d< \n", i2);

result is

>+12345 <

can you explain me did the comma go between 012 and y the - symbol was not inserted....

Meena R. Krishnan
Ranch Hand

Joined: Aug 13, 2006
Posts: 178
System.out.printf(">%0,7d< \n", i2);
System.out.format(">%+-7d< \n", i2);

7 represents the width of the output.
0 --> pad the o/p with zeros until it is of width 7
- --> left justifies the number and won't add - to the o/p
, --> is a grouping_separator.
I agree. Here's the link:
subject: Boxing n Auto boxing-marcus green
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