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A real-world analogy
Consider the following analogous situation. A young family has a large playscape for their children in their back yard. They need to move to anotherhouse across town. In order to save money, they rent a small truck and do the entire move themselves.
A playscape object
The playscape can be thought of as an object with certain properties such as swing and slide .
It is too large to fit into the truck so the adults disassemble it into a well-organized package of boards, chains, bolts, nuts, etc. They are very careful to label each part and to create somedrawings showing the organization of the parts for use later.
No longer an object
In that disassembled state, it can no longer be thought of as an object with properties of swing and slide . Instead, it is simply a well-organized and documented package of parts. The package ofparts is analogous to a JSON string. The playscape object has been transformed into a well-organized package of parts.
Reassemble the parts
After the parts are transported to the new location, they are reassembled into an object with properties of swing and slide .
This is what we do with JSON. We disassemble an object (or other data construct) into a JSON string: a well-organized package of parts. Later on, and possibly in an entirely different programming environment, we reassemble theparts into a data construct suitable for use in the new programming environment.
Streamlined procedures
JavaScript, Java, PHP, and other programming languages provide streamlined procedures for transforming a data construct into a JSON string and fortransforming a JSON string into a suitable data construct. As an example, the JSON.stringify method can be used to transform a JavaScript object into a JSON string. The JSON.parse method can be used to transform a JSON string into a JavaScript object. Other methods or functions areavailable to accomplish the same purposes in other languages.
There are many good online JSON references. Here are a few:
The next module will present and explain some sample scripts that show how to use JSON with JavaScript.
This section contains a variety of miscellaneous information.
Financial : Although the Connexions site makes it possible for you to download a PDF file for thismodule at no charge, and also makes it possible for you to purchase a pre-printed version of the PDF file, you should beaware that some of the HTML elements in this module may not translate well into PDF.
I also want you to know that, I receive no financial compensation from the Connexions website even if you purchase the PDF version of the module.
In the past, unknown individuals have copied my modules from cnx.org, converted them to Kindle books, and placed them for sale on Amazon.com showing me as the author. Ineither receive compensation for those sales nor do I know who does receive compensation. If you purchase such a book, please beaware that it is a copy of a module that is freely available on cnx.org and that it was made and published withoutmy prior knowledge.
Affiliation : I am a professor of Computer Information Technology at Austin Community College in Austin, TX.
-end-
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