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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

how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
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Do somebody tell me a best nano engineering book for beginners?
s. Reply
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are you nano engineer ?
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s. Reply
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Do you know which machine is used to that process?
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s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
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Sanket Reply
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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
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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
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Prasenjit Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
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