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Print an uninitialized local variable

The statement in the following code fragment attempts to fetch and print a value using the uninitialized local variable named ref .

void doIt(){ char[]ref; System.out.print(ref);

As a result, the program refuses to compile, displaying the following error message under JDK 1.3.

Ap158.java:23: variable ref might not have been initialized System.out.print(ref);

Back to Question 8

Answer 7

See explanation below.

Explanation 7

The javadoc.exe program

When you download the JDK from Oracle, you receive a program named javadoc.exe in addition to several other programs.

The purpose of the javadoc program is to help you document the Java programs that you write. You create the documentation by running the javadoc program and specifying your source file or files as a command-line parameter. Forexample, you can generate documentation for this program by entering the following at the command line.

javadoc Ap157.java

Produces HTML files as output

This will produce a large number of related HTML files containing documentation for the class named Ap157 . The primary HTML file is named Ap157.html . A file named index.html is also created. This file can be opened in a browser to provide a viewer for all of theinformation contained in the many related HTML files.

(As a labor saving device, you can also specify a group of input files to the javadoc program, using wildcard characters as appropriate, to cause theprogram to produce documentation files for each of the input files in a single run.)

Special documentation comments and directives

If you include comments in your source code that begin with


and end with


they will be picked up by the javadoc program and become part of the documentation.

In addition to comments, you can also enter a variety of special directives to the javadoc program as shown in the following program.

public class Ap157{/** * Returns the character at the* specified index. An index ranges from *<code>0</code>to *<code>length() - 1</code>. ** @param index index of desired * character.* @return the desired character. */public char charAt(int index) { //Note, this method is not intended// to be operational. Rather, it // is intended solely to illustrate// the generation of javadoc // documentation for the parameter// and the return value. return 'a';//return dummy char}//end charAt method }//end class

The @param and @return directives

The @param and @return directives in the source code shown above are used by the javadoc program for documenting information about parameters passed to and information returned from the method named charAt . The method definition follows the special javadoc comment.

Back to Question 7

Answer 6


Explanation 6

Public classes in separate files

This program meets the requirement identified in Question 5 . In particular, this program defines two public classes. The source code for each public classis stored in a separate file. Thus, the program compiles and executes successfully, producing the text OK on the screen.

Questions & Answers

what is math number
Tric Reply
x-2y+3z=-3 2x-y+z=7 -x+3y-z=6
Sidiki Reply
Need help solving this problem (2/7)^-2
Simone Reply
what is the coefficient of -4×
Mehri Reply
the operation * is x * y =x + y/ 1+(x × y) show if the operation is commutative if x × y is not equal to -1
Alfred Reply
An investment account was opened with an initial deposit of $9,600 and earns 7.4% interest, compounded continuously. How much will the account be worth after 15 years?
Kala Reply
lim x to infinity e^1-e^-1/log(1+x)
given eccentricity and a point find the equiation
Moses Reply
12, 17, 22.... 25th term
Alexandra Reply
12, 17, 22.... 25th term
College algebra is really hard?
Shirleen Reply
Absolutely, for me. My problems with math started in First grade...involving a nun Sister Anastasia, bad vision, talking & getting expelled from Catholic school. When it comes to math I just can't focus and all I can hear is our family silverware banging and clanging on the pink Formica table.
I'm 13 and I understand it great
I am 1 year old but I can do it! 1+1=2 proof very hard for me though.
Not really they are just easy concepts which can be understood if you have great basics. I am 14 I understood them easily.
find the 15th term of the geometric sequince whose first is 18 and last term of 387
Jerwin Reply
I know this work
The given of f(x=x-2. then what is the value of this f(3) 5f(x+1)
virgelyn Reply
hmm well what is the answer
If f(x) = x-2 then, f(3) when 5f(x+1) 5((3-2)+1) 5(1+1) 5(2) 10
how do they get the third part x = (32)5/4
kinnecy Reply
make 5/4 into a mixed number, make that a decimal, and then multiply 32 by the decimal 5/4 turns out to be
can someone help me with some logarithmic and exponential equations.
Jeffrey Reply
sure. what is your question?
okay, so you have 6 raised to the power of 2. what is that part of your answer
I don't understand what the A with approx sign and the boxed x mean
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
I'm not sure why it wrote it the other way
I got X =-6
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
oops. ignore that.
so you not have an equal sign anywhere in the original equation?
is it a question of log
I rally confuse this number And equations too I need exactly help
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Commplementary angles
Idrissa Reply
im all ears I need to learn
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greetings from Iran
salut. from Algeria
A soccer field is a rectangle 130 meters wide and 110 meters long. The coach asks players to run from one corner to the other corner diagonally across. What is that distance, to the nearest tenths place.
Kimberly Reply
Jeannette has $5 and $10 bills in her wallet. The number of fives is three more than six times the number of tens. Let t represent the number of tens. Write an expression for the number of fives.
August Reply
What is the expressiin for seven less than four times the number of nickels
Leonardo Reply
How do i figure this problem out.
how do you translate this in Algebraic Expressions
linda Reply
why surface tension is zero at critical temperature
I think if critical temperature denote high temperature then a liquid stats boils that time the water stats to evaporate so some moles of h2o to up and due to high temp the bonding break they have low density so it can be a reason
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris Reply
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Source:  OpenStax, Object-oriented programming (oop) with java. OpenStax CNX. Jun 29, 2016 Download for free at https://legacy.cnx.org/content/col11441/1.201
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