Parsing Xml/json in iOS

JSON data format

1. Overview:
JSON (JavaScript Object Notation) is a lightweight data interchange format

Based on the text format, easy to read and write, but also easy to machine analysis and build.

2. The format of the JSON data is: name/value • The name is written in the front face (in double quotes)
• Value pairs are written on the back face
• Middle? Separated by a colon

3. JSON value? Type of support

• Number (integer or floating point)

• String (in double quotes)

• Logical value (TRUE or FALSE)

• Array (in brackets)

• Object (in curly braces)

• Null

JSON format? One: The outermost is? curly braces

Online JSON format? Tool http://json.phpddt.com

Url:

Http://api.openweathermap.org/data/2.5/weather?q=beijing&units=metric

JSON format? Two: The outermost is the middle bracket

1. JSON value? The correspondence between the supported types and OC objects

• Digital-NSNumber

• Double quote-NSString

• Nsarray, Brackets

• ? curly Braces--nsdictionary

• Null-> NSNull

  2. Object to model: Convert the parsed OC object (nsarray/nsdictionary) to a custom model class

XML data format

1. XML (extensible Markup Language) Extensible Markup Word,
• Is it a type of marker that is used to mark the electrical sub-document so that it has a structured markup language?
XML is a common language used in the transfer of data between various applications.

2. Three terms for XML documents:

• root element: Outermost element

• Element: From the start tag until the end of the label's section

• Attribute (Attribute): Provides additional information about the element

1. XML sample?:

2. XML sample? Two:

1. XML parsing? Mode:

• DOM:? Load the entire XML document into memory at once, through the element structure within the XML document, parse out the element pair

  Expected value/attribute

• SAX: Starting with the root element of the XML document, parsing the elements sequentially

  2. Parsing XML in iOS? Document CLASS/Library

  • Gdataxml:dom analysis, developed by Google, based on LIBXML2

  • Nsxmlparser:sax the method of analysis, making it relatively simple

    3. Example: Parsing XML with gdataxml? Documents and configurations:

    A. gdataxml/folder guide into Xcode project
    B. "Header Search Paths" in Build setting add/usr/include/libxml2c. "Other Linker Flags" in Build setting add-LXML2

Parsing Xml/json in iOS