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The moose likes Programmer Certification (SCJP/OCPJP) and the fly likes KB page no 547 Big Moose Saloon
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KB page no 547

sumaraghavi ragha
Ranch Hand

Joined: Nov 17, 2006
Posts: 118
Hi all,

Please explin me why

line one priting true and line 2 false.

Thanks in advance
fred rosenberger
lowercase baba

Joined: Oct 02, 2003
Posts: 11814

for those of use who do not have the book, could you elaborate a little more on the code?

There are only two hard things in computer science: cache invalidation, naming things, and off-by-one errors
Ken Truitt
Ranch Hand

Joined: Aug 23, 2007
Posts: 124
List<String> test = new ArrayList<String>();
String s = "hi";

size() is called, and result, 3, is printed;
"string", "hi", and "hihi" are added to the list;
contains(42) is called, and the result, false, is printed;
contains("hihi") is called, and the result, true, is printed;
remove("hi") removes middle element;
size() is called and result, 2, is printed.

SCJP 88% | SCWCD 84%
Ram Reddy
Ranch Hand

Joined: Feb 20, 2007
Posts: 88
List<String> test = new ArrayList<String>();

Here test is a list reference can only contain the Strings.
When what is the use of checking other types ( here 42 Integer) in test by using contains method?
why API written for contains method accepting the object of type 'Object'.
Can any one calrify me about this?

It is sorta covered in the JavaRanch Style Guide.
subject: KB page no 547
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