Key Words

[Mahesh Bansal]

Can someone please explain that in case a questions is there that which of these are keywords
1) true
2) false
3) null
Are these keywords or not.
Thanks
Mahesh

[Ishaan Mohan]

Yes they are keywords.

[Sandy Lee]

I thing true, false and null are not keywords.
They are literals.

[Jane Griscti]

Hi Mahesh,
true and false are boolean literals
null is a null literal
While they are not, technically, keywords, you cannot use them as identifier names ie you can't name a variable, method or class true, false or null.
Hope that helps.
------------------
Jane Griscti
Sun Certified Java 2 Programmer
"When ideas fail, words come in very handy" -- Goethe

[Howard Hu]

Does the real test ask you to differentiate keywords from reserved words? What is the rule to differentiate those two?
Thanks
--Howard

[Ishaan Mohan]

Yes All threee are Literals but from Exam point of view I think If question is select Keywords and options are :
a) true
b) false
c) string
d) short
e) null
then answer will be a,b,d and e.
(all mocks exams are considering them as a keywords.)

[Angela Poynton]

When you have a question it is worth looking at the Programmer Certification FAQ to see if it has been answered you can find that here http://www.javaranch.com/certfaq.jsp#q1 ... if it's not there it's also worth doing a search using a key word from you question to see what you can find. http://www.javaranch.com/cgi-bin/ubb/search.cgi?action=intro&default=24

[Mahesh Bansal]

But my question still remains answered. Whether in the exam if literals are given and question is are these keywords ?
Should we say true or false.
Thanks for the advice.
Mahesh

[Jane Griscti]

Mahesh,
The best approach to take is to watch the wording of the question. If it says "what words cannot be used as identifiers" and the answer list includes true, false, null or any keyword then you would select them.
If the question asks "which are not Java keywords" and the answer list includes true, false or null, I would select them as not being keywords.
If the question asks "which words are reserved in Java"; select any keywords and true, false or null if they are listed.
The exam questions on keywords tend to include captialized words or C words (they're always trying to catch out C coders) so I don't think the real questions will cause you much anxiety.
Hope that helps.
------------------
Jane Griscti
Sun Certified Java 2 Programmer
"When ideas fail, words come in very handy" -- Goethe

[Rat Ban]

hi all,
According to RHE ....
"true","false","null" r all keywords.
Ratul Banerjee

[Sandeep Meher]

Hi,
1. According to the Sun's Java tutorial:
a. reserved words = keywords (including goto and const) + the literals null, true, false
2. According to the Java Language Specification:
a. keywords (include goto and const) are reserved
b. null, true, false are not keywords but literals
Regards,
Sandeep.

[Mahesh Bansal]

Thanks a lot for clearing the doubts.
Mahesh