<< Chapter < Page Chapter >> Page >
This module takes a preliminary look at arrays and strings. More in-depth discussions will be provided in future modules.

Revised: Mon Mar 28 16:20:59 CDT 2016

This page is included in the following Books:

Table of contents


This module takes a preliminary look at arrays and strings. More in-depth discussions will be provided in future modules. For example, you will find a more in-depth discussions of array objects in the followingmodules:

Viewing tip

I recommend that you open another copy of this module in a separate browser window and use the following links to easily find and view the Figuresand Listings while you are reading about them.


  • Figure 1 . Formats for declaring a reference variable for an array object.
  • Figure 2 . Allocating memory for the array object.
  • Figure 3 . Declaration and instantiation can be separated.
  • Figure 4 . General syntax for combining declaration and instantiation.
  • Figure 5 . An example of array indexing syntax.
  • Figure 6 . The use of the length property in the conditional clause of a for loop.
  • Figure 7 . A string literal.
  • Figure 8 . String concatenation.
  • Figure 9 . Declaring and instantiating a String array.
  • Figure 10 . Allocating memory to contain the String objects.



The first step

The first step in learning to use a new programming language is usually to learn the foundation concepts such as variables, types,expressions, flow-of-control, arrays, strings, etc. This module concentrates on arrays and strings.

Array and String types

Java provides a type for both arrays and strings from which objects of the specific type can be instantiated. Once instantiated, the methodsbelonging to those types can be called by way of the object.


Arrays and Strings

Java has a true array type and a true String type with protective features to prevent your program from writing outside the memorybounds of the array object or the String object. Arrays and strings are true objects.

Declaring an array

You must declare an array before you can use it. (More properly, you must declare a reference variable to hold a reference to the array object.) In declaring the array, you must provide two important pieces of information:

  • the name of a variable to hold a reference to the array object
  • the type of data to be stored in the elements of the array object

Different declaration formats

A reference variable capable of holding a reference to an array object can be declared using either format shown in Figure 1 . (I personally prefer the first option because I believe it is more indicative ofthe purpose of the declaration. However, both options produce the same result -- a reference variable capable of storing a reference to an array object.)

Questions & Answers

how do you translate this in Algebraic Expressions
linda Reply
why surface tension is zero at critical temperature
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
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
I'm interested in nanotube
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
what is system testing
what is the application of nanotechnology?
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
anybody can imagine what will be happen after 100 years from now in nano tech world
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
silver nanoparticles could handle the job?
not now but maybe in future only AgNP maybe any other nanomaterials
I'm interested in Nanotube
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
bamidele Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
Got questions? Join the online conversation and get instant answers!
QuizOver.com Reply

Get the best Algebra and trigonometry course in your pocket!

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
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Object-oriented programming (oop) with java' conversation and receive update notifications?