JS Web Development Flashcards
What is JSON?
a universally readable data interchange format that follows JavaScript object syntax
What are serialization and deserialization?
serialization: converting an object into a string
deserialization: turning the string back into the same object
Why are serialization and deserialization useful?
useful because they let you send data in a universally readable format
How do you serialize a data structure into a JSON string using JavaScript?
JSON.stringify()
How do you deserialize a JSON string into a data structure using JavaScript?
JSON.parse()
What is a client?
The application that is requesting a service or function
What is a server?
The application that is providing a service or resource
Which HTTP method does a browser issue to a web server when you visit a URL?
GET
What three things are on the start-line of an HTTP request message?
- The HTTP method (ex. GET, POST, DELETE, PUT, etc)
- Request target (a url including any query string)
- The HTTP version
What three things are on the start-line (aka status line) of an HTTP response message?
- The protocol version
- A status code/response code indicating success or failure of request (ex 200, 404)
- A status text; a brief human-readable description of status code (ex. ‘Not Found’, ‘OK’)
What are HTTP headers?
HTTP headers let the client or server pass additional information with an HTTP request or response.
Is a body required for a valid HTTP request or response message?
No, the message body is optional
What is AJAX?
Anything that makes a request to an outside source and then updates a web page after it has been loaded.
Ajax allows you to request data from a server and load it without having to refresh page
What does the AJAX acronym stand for?
Asynchronous Javascript and XML
This is what the letters literally stand for; but the term AJAX as it’s used today does not specifically mean this.
Which object is built into the browser for making HTTP requests(network requests) in JavaScript?
The XMLHttpRequest object
What event is fired by XMLHttpRequest objects when they are finished loading the data from the server?
The load event
An XMLHttpRequest object has an addEventListener() method just like DOM elements. How is it possible that they both share this functionality?
Both DOM elements and the XMLHttpRequest object inherit this method through prototypal inheritance from the EventTarget object
