Tutorial about web service

Can anyone give me good tutorial about web service? i find below tutorial with example but doesn't work

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for example if i want t开发者_开发百科o show weather in my app should i get data from specific web site or i can get data from yahoo or other site about weather

SajjadZare,

I answered a similar question on SO and wrote a blog post about consuming Web APIs. Please let me know if this doesn't help you:

How to Consume JSON or XML Web APIs on the iPhone

The original SO question I answered

Cheers and best of luck,

Mark