Web Technologies Quiz

JSON Basics

• JSON (JavaScript Object Notation) represents structured data using a key/value pair format.
• Example of JSON: {"name": "John"}.
• JavaScript objects can be converted into JSON using JSON.stringify(obj) and JSON can be parsed into JavaScript objects with JSON.parse(myJSON).

Comparison: JSON vs XML

• JSON is becoming more popular due to its simplicity and compactness compared to XML (Extensible Markup Language).
• XML has been used for over 30 years and is crucial for many web applications, providing structured data interchange.

Characteristics of JSON

• JSON is strictly a data format, making it lightweight and easy to read.
• Data is stored in map format using key/value pairs, which allows for straightforward access and manipulation.
• Example JSON data structure for employees:

  {
    "employees": [
      {"firstName":"John", "lastName":"Doe"},
      {"firstName":"Anna", "lastName":"Smith"},
      {"firstName":"Peter", "lastName":"Jones"}
    ]
  }
  

Characteristics of XML

• XML utilizes a markup language, comprising data with descriptive tags.
• XML data is represented as a tree structure, which may become bulky and complex.
• Supports complex data types like charts and images while being verbose in nature.

Performance and Usability

• JSON is typically faster to parse and transfer compared to XML due to its smaller size.
• XML supports namespaces, comments, and metadata, while JSON does not provide these features.
• JSON supports direct arrays, making it easier to handle lists.

Security Considerations

• XML is vulnerable to external entity expansion attacks if not correctly managed.
• JSON is considered safe to parse, though using JSONP can expose the application to Cross-Site Request Forgery (CSRF) vulnerabilities.

Data Serialization and Manipulation

• XML serialization can be done using XMLSerializer, converting DOM structures to XML strings.
• JSON is easy to manipulate and directly utilizes JavaScript syntax for data interchange.

Language Independence

• JSON, while inspired by JavaScript, is language-independent and can be used across different programming environments, enhancing its versatility.

Summary of Key Differences between XML and JSON

• XML is a markup language, whereas JSON is purely a data format in JavaScript.
• Parsing XML is generally slower due to its bulky structure, while JSON is lightweight and quicker to process.
• XML supports more complex data types and structures; JSON favors readability and simplicity.

JSON Structure and Syntax

• JSON syntax consists of name/value pairs, where field names are in double quotes followed by a colon and the value.
• Values in JSON can include strings, numbers, objects, arrays, Booleans, or null, making it a versatile data format.