Flash cards
Review the key moves
What is the main idea behind JSON vs XML?
Lesson checks
Practice each idea before moving on
Short Mimo-style checks built from this lesson's code, terms, and sequence.
Which statement best captures the main point of this lesson?
Complete the missing token from the example code.
{"___":[Put the learning moves in the order that makes the concept easiest to apply.
Both JSON and XML can be used to receive data from a web server.
The following JSON and XML examples both define an employees object, with an array of 3 employees:
JSON Example
{"employees":[
{ "firstName":"John", "lastName":"Doe" },
{ "firstName":"Anna", "lastName":"Smith" },
{ "firstName":"Peter", "lastName":"Jones" }
]}XML Example
<employees>
<employee>
<firstName>John</firstName> <lastName>Doe</lastName>
</employee>
<employee>
<firstName>Anna</firstName> <lastName>Smith</lastName>
</employee>
<employee>
<firstName>Peter</firstName> <lastName>Jones</lastName>
</employee>
</employees>JSON is Like XML Because
- Both JSON and XML are "self describing" (human readable)
- Both JSON and XML are hierarchical (values within values)
- Both JSON and XML can be parsed and used by lots of programming languages
- Both JSON and XML can be fetched with an XMLHttpRequest
JSON is Unlike XML Because
- JSON doesn't use end tag
- JSON is shorter
- JSON is quicker to read and write
- JSON can use arrays
The biggest difference is
XML has to be parsed with an XML parser. JSON can be parsed by a standard JavaScript function.
Why JSON is Better Than XML
XML is much more difficult to parse than JSON. JSON is parsed into a ready-to-use JavaScript object.
For AJAX applications, JSON is faster and easier than XML:
Using XML
- Fetch an XML document
- Use the XML DOM to loop through the document
- Extract values and store in variables
Using JSON
- Fetch a JSON string
- JSON.Parse the JSON string