I have an app which will load content from a website.
There will be around 100 articles during every loading.
I would like to know which way is better to load content from web if we look at:
JSON is better if your data is huge
read more here
http://www.json.org/xml.html
Strongly recommend JSON for better performance and less bandwidth consumption.
JSON all the way. The Saad's link is an excellent resource for comparing the two (+1 to the Saad), but here is my take from experience and based on your post:
speed
JSON is likely to be faster in many ways. Firstly the syntax is much simpler, so it'll be quicker to parse and to construct. Secondly, it is much less verbose. This means it will be quicker to transfer over the wire.
compatiblity
In theory, there are no issues with either JSON or XML here. In terms of character encodings, I think JSON wins because you must use Unicode. XML allows you to use any character encoding you like, but I've seen parsers choke because the line at the top specifies one encoding and the actual data is in a different one.
experience
I find XML to be far more difficult to hand craft. You can write JSON in any text editor but XML really needs a special XML editor in order to get it right.
XML is more difficult to manipulate in a program. Parsers have to deal with more complexity: name spaces, attributes, entities, CDATA etc. So if you are using a stream based parser you need to track attributes, element content, namespace maps etc. DOM based parsers tend to produce complex graphs of custom objects (because they have to in order to model the complexity). I have to admit, I've never used a stream based JSON parser, but parsers producing object graphs can use the natural Objective-C collections.
On the iPhone, there is no built in XML DOM parser in Cocoa (you can use the C based parser - libxml2) but there is a simple to use JSON parser as of iOS 5.
In summary, if I have control of both ends of the link, I'll use JSON every time. On OS X, if I need a structured human readable document format, I'll use JSON.
You say you are loading "articles". If you mean documents containing rich text (stuff like italic and bold), then it's not clear that JSON is an option - JSON doesn't really do mixed content.
If it's pure simple structured data, and if you don't have to handle complexities like the need for the software at both ends of the communication to evolve separately rather than remaining in lock sync, then JSON is simpler and cheaper: you don't need the extra power or complexity of XML.
