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III. Objective-C and Foundation > 23. Writing Files with NSString and NSData

23
Writing Files with NSString and NSData

The Foundation framework gives the developer a few easy ways to read from and write to files. In this chapter, you’ll try a few of them out.

Writing an NSString to a file

First, let’s see how you would take the contents of an NSString and put it into a file. When you write a string to a file, you need to specify which string encoding you are using. A string encoding describes how each character is stored as an array of bytes. ASCII is a string encoding that defines the letter ‘A’ as being stored as 01000001. In UTF-16, the letter ‘A’ is stored as 0000000001000001.

The Foundation framework supports about 20 different string encodings. UTF can handle an incredible collection of writing systems. It comes in two flavors: UTF-16, which uses two or more bytes for every character, and UTF-8, which uses one byte for the first 128 ASCII characters and two or more for other characters. For most purposes, UTF-8 is a good fit.


  

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