|
|
Computing |
Java
Arrays
and Overloading
in Java
In the last article, we dealt with strings,
variable initializations and castings. This week lets have a look at the
array feature of java and also on a special feature called Operator
Overloading.
Arrays in Java
-
Java has a built in array class which you can use to hold multiple
values provided those values are of the same data type.
-
In Java, arrays are much more restrictive. For example, you may not
change the size of an array once you have created it. To add elements
to an array dynamically you actually have to create a new, larger
array and copy the old array into the new one using array Copy() in
the java.lang.System class.
-
For a dynamically resizable data structure, look to the Vector class
in the java.utilpackage.
-
However, for cases in which you do not need to dynamically resize your
data structure, arrays work great. Java provides a zero-based array,
which is defined much as variables are. You first declare what type of
data will be stored in an array, give the array a name, and then
define how large it is. Consider the following example:
int[] intArray = new int[40];
This array would hold 40 ints numbered from 0-39.
-
Filling and extracting values from an array is the same process as it
was for Perl.
Consider the following example:
int[] intArray = new int[40];
for (int i = 0; i < 40; i++)
{
intArray[i] = i;
}
for (int i = 0; i < 40; i++)
{
System.out.println("Value: " + intArray[i]);
}
-
Java also allows you to define an array at time of initialization such
as in the following example:
int[] intArray = {0,1,2,3,4};
-
Operator Overloading
Another cool feature of Java is that methods in Java can easily be
overloaded such that the same method name can be used for several
different implementations of the same action. For example printNumber(),
printLetter(), printImage() are the various methods that can be used
for several different implementations of the same action.
-
The only requirement for overloading is that each version of the
method takes a different set of parameters as arguments (sometimes, we
say that it has a "different signature") such as in the following
example:
int add(int a, int b)
{
return (a+b);
}
float add(float a, float b)
{
return (a+b);
}
-
Finally, it is worth noting that since methods belong to specific
classes, it is fine for you to have the same method name with the same
arguments in different classes. Thus, the Button class might have a
setLabel(String s) method and a Label might have a setLabel(String s)
method and neither will conflict since each method is specific to a
specific class.
–
Deepak Chandrasekaran
February 7, 2002
Articles on Java
By Deepak Chandrasekaran
JAVA: A Beginner's Guide
Oops... I did it Again!
Objects and Classes
First Java Application
Your First Java Applet
Statements and Expressions
Variable Type & Declaration
Variables and Strings
Arrays and Overloading in JAVA
By Neeraj Mathur
Java – Man Not Again!
Common Misconceptions About Java
By Ruchi Gupta
Java Virtual Machine
Computing
CC++ |
Flash |
Internet Security
Linux |
Networking
General Articles
Top
|
|
