JSON vs XML

JSON 和 XML 均可用于从 web 服务器接收数据。

下面的 JSON 和 XML 实例都定义了雇员对象，包含了由 3 个雇员构成的数组：

JSON 实例

{"employees":[
    { "firstName":"Bill", "lastName":"Gates" },
    { "firstName":"Steve", "lastName":"Jobs" },
    { "firstName":"Elon", "lastName":"Musk" }
}]

XML 实例

<employees>
    <employee>
         <firstName>Bill</firstName>
         <lastName>Gates</lastName>
     </employee>
     <employee>
         <firstName>Steve</firstName>
         <lastName>Jobs</lastName>
     </employee>
     <employee>
         <firstName>Elon</firstName>
         <lastName>Musk</lastName>
     </employee>
</employees>

JSON is similar to XML because:

  • Both JSON and XML are 'self-descriptive' (human-readable)
  • Both JSON and XML are hierarchical (values contain values)
  • Both JSON and XML can be parsed and used by a large number of programming languages
  • Both JSON and XML can be read by XMLHttpRequest

The differences between JSON and XML are:

  • JSON does not use tags
  • JSON is shorter
  • JSON has faster read/write speed
  • JSON can use arrays

The biggest difference is:

XML must be parsed using an XML parser. JSON, on the other hand, can be parsed using standard JavaScript functions.

Why is JSON better than XML?

  • XML is more difficult to parse than JSON.
  • JSON is parsed into a JavaScript object that can be used.

For AJAX applications, JSON is faster and easier to use than XML:

Use XML

  • Read XML Document
  • Use XML DOM to traverse the document
  • Extract the value stored in the variable

Use JSON

  • Read JSON String
  • JSON.Parse JSON String