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There is nothing new in Listing 1 so that code shouldn't require further explanation. Note however, that the name "Tom" will become significant in alater discussion.

Instantiate and populate a JSONArray object

The code in Listing 2 instantiates and populates a JSONArray object.

Listing 2 . Instantiate and populate a JSONArray object. JSONArray arrayListA = new JSONArray(); arrayListA.add("2-club");arrayListA.add("3-heart"); arrayListA.add("4-diamond");arrayListA.add("5-spade");

Previous pages in this book have constructed JSON strings using a subclass of the Java HashMap class -- (the JSONObject class) . It is worth noting that JSON strings constructed in that manner are unordered.However, JSON arrays constructed using the JSONArray class, which is a subclass of the ArrayList class, are ordered lists.

The program that I will explain in this page is intended to represent the beginning state of a two-person card game where each player receives four cards.The code in Listing 2 constructs a list of the cards that will be dealt to one of the players.

Populate hashMapA with a key/value pair

The code in Listing 3 populates the JSONObject object referred to as hashMapA with a key/value pair where the key is "cards" and the value is an object of the JSONArray class containing a list of strings naming specific playing cards.

Listing 3 . Populate hashMapA. hashMapA.put("cards",arrayListA);

Note that hashMapA already contained a key/value pair identifying one of the players in the game named "Tom" (see Listing 1 ). Thus the code in Listing 1 through Listing 3 can be though of as "dealing" the cards identified in Listing 2 to the player named "Tom".

Create and populate another similar JSON object

Listing 4 creates and populates a second list of playing cards and deals them to the second player in the game whose name is "Joe".

Listing 4 . Create and populate another similar JSON object. JSONObject hashMapB = new JSONObject(); hashMapB.put("name","Joe");JSONArray arrayListB = new JSONArray();arrayListB.add("4-heart"); arrayListB.add("5-heart");arrayListB.add("6-club"); arrayListB.add("7-diamond");hashMapB.put("cards",arrayListB);

Put the players in the game

Now that the players have been created and have received their cards, it is time to put them in the game.

Listing 5 begins by adding the two players and their card arrays to a new object of type JSONArray . This results in nested arrays.

Listing 5 . Put the players in the game. JSONArray arrayListC = new JSONArray(); arrayListC.add(hashMapA);arrayListC.add(hashMapB); JSONObject hashMapC = new JSONObject();hashMapC.put("game",arrayListC);

Then Listing 5 creates a new JSONObject object to represent the game and populatesit with a key/value pair where the key is "game" and the value is the array containing the two players and their card arrays.

Write the JSON string to an output file

Listing 6 calls the writeJSONString method on the JSONObject object to encode the object into a JSON string and write it to an output filenamed junk.json .

Listing 6 . Write the JSON string to an output file. try{ PrintWriter out =new PrintWriter(new File("junk.json")); hashMapC.writeJSONString(out);out.flush(); }catch(IOException ex){ex.printStackTrace(); }//end catch}//end main }//end class Code

Questions & Answers

what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit 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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