HTML, CSS, Bootstrap, JavaScript

Question 1

What is HTML?

Answer 1

Hyper Text Markup Language, used to define how a web page is laid out using tags.

Question 2

What is CSS?

Answer 2

Cascading Style Sheet which defines how elements will look on the web page.

Question 3

How can CSS be applied?

Answer 3

• External - In a separate file that’s linked.
• Internal - At the top of the document in style tags.
• Inline - as an attribute on the elements themselves.

Question 4

What is iFrame?

Answer 4

• An HTML document embedded inside another HTML document on a website.
• The IFrame element is used to insert content from another source, like an ad on a web page.

Question 5

What is DOM?

Answer 5

Document Object Model, represents the html page structure as nodes and objects.

Question 6

What is Bootstrap?

Answer 6

A front-end, open source toolkit used to speed up development with HTML, CSS, and JavaScript.
Built for mobile first web-development using a grid system.

Question 7

What are Meta Tags?

Answer 7

• Provide metadata about the HTML document.
• Metadata will not be displayed on the page, but will be machine parsable.
• Meta elements are typically used to specify page description, keywords, author of the document, last modified, and other metadata

Question 8

What is ASCII?

Answer 8

• American standard code information interchange

- A character encoding standard for electric communication.

Question 9

What is UTF-8?

Answer 9

• Unicode Transformation Format
• 8 means it uses 8 bit blocks to represent a character
• A character encoding that can contain any unicode characters

Question 10

What tag would you use to create tables?

Answer 10

• The table tag
• Th is table head
• Tr is table row
• Td is table data (column data)

Question 11

What are the types of lists?

Answer 11

• Ordered list
  
  • Ol
  • li
• Unordered list
  
  • Ul
  • li
• Description list
  
  • Dl
  • Dt
  • Dd

Question 12

What does attribute “required” do?

Answer 12

Used on input to specify that it must be filled out for the form to submit.

Question 13

What does attribute ‘target=”_blank”’ do?

Answer 13

• Anchor links may have the target attribute which controls what happens when the anchor is clicked.
• If the target is _blank this tells the browser to open a new window (or tab depending on user settings) when the link is clicked.

Question 14

JavaScript and AJAX

Answer 14

• JavaScript is an object oriented interpreted scripting language
  -Used on web pages for DOM manipulation to make
  the pages more interactive.
• AJAX stands for Asynchronous JavaScript and XML.
  
  • A new technique for creating better, faster, and more interactive web applications using XML, HTML, CSS, and JavaScript

Question 15

Is JavaScript loosely typed or strict typed?

Answer 15

JavaScript is loosely typed you don’t declare the data types of variables explicitly.

Question 16

Is JavaScript case-sensitive?

Answer 16

Yes

Question 17

What is Prototypical Inheritance?

Answer 17

• Everything in javascript is an object
• Each object has a private property which holds a link to another object called its prototype.
• When you construct an object the prototype chain links all the way up to Object the parent of everything in javascript to build the object.

Question 18

Is JavaScript Pass-By-Value or Pass-By-Reference?

Answer 18

• For primitives javascript is pass by value.
• Javascript also uses call by sharing for objects.
  Call by sharing is similar to pass by reference in that the function is able to modify the same mutable object but unlike pass by reference isn’t able to assign directly over it.

Question 19

What is Type Coercion?

Answer 19

• Type coercion is a property of javascript to attempt to compare values of different types because it doesn’t have strict types
• When == is done it will try to change the type of the object for a temporary comparison.
• A good example is (1 == ‘1’ will be true, even though one is a string and one is a number).
  This can be avoided by using === which won’t try to do any casting.

Question 20

What are the variable scopes in JavaScript?

Answer 20

Global and local scope

Question 21

What are functions in JavaScript?

Answer 21

• Functions are objects to start
• A function object defines a series of tasks and/or calculates a value.
• Must be defined in the scope you wish to call it in.

Question 22

What are the types of functions?

Answer 22

• Function declaration - create a function but don’t assign it to a variable
• Function expression - create a function and assign it to a variable

Question 23

What is an anonymous function?

Answer 23

• A function that is created at runtime.
• The function operator can be used anywhere that it’s valid to use an expression.
• Called “anonymous” because the function was not “named”

Question 24

What is a self-invoking function?

Answer 24

• A self-invoking function is started automatically without being called, this is done right after it’s created.
• This is used for avoiding naming conflict as well as for achieving encapsulation.
• Variables or declared objects are not accessible outside this function.

Question 25

What is Hoisting?

Answer 25

Hoisting in javascript is when the interpreter moves all variable and function declarations to the top of the current scope.

Question 26

What are Closures?

Answer 26

- A closure is an inner function that has access to the outer functions variables. - A closure has three scope chains: its own scope, outer functions, and globals.

Question 27

JSON vs JS Object

Answer 27

- JSON is JavaScript Object Notation - JSON is a data interchange format, a way to pass structured information between languages. - JSON is formatted similarly to how a JavaScript Object is formatted which makes it very easy to parse and build objects from. - JSOBject can hold funcitons, and have undefined values, JSON cannot

Question 28

What does it mean to be "Truthy"?

Answer 28

Javascript doesn’t use true and false when doing logical comparisons JavaScript uses type coercion, truthy is not just the value true, it’s values that could logically represent a true value.

Question 29

What are the falsy values in javascript

Answer 29

Falsy values could be false, null, undefined, NaN, zero, and empty strings.

Question 30

What are the data types in JavaScript?

Answer 30

``` String Number Boolean Undefined Arrays Objects Symbols Function ```

Question 31

What is Capturing?

Answer 31

- Capturing is another form of event propagation. - Capturing works the opposite of bubbling: - When an event is fired and parent and children elements have handlers registered the parent’s handler fires first and then the event trickles down to the child.

Question 32

What is Bubbling?

Answer 32

- Event bubbling is a form of event propagation. - Event bubbling propagates events from children to parents. - An event gets fired and is handled by a child element, from there it propagates up to parents with handlers for the event.

Question 33

What are events?

Answer 33

HTML events are actions generated with user interaction with an element or elements.

Question 34

What is a Listener?

Answer 34

A listener is an object that waits for events or actions to occur.

Question 35

What is AJAX?

Answer 35

- Asynchronous JavaScript and XML. AJAX is a new technique for creating better, faster, and more interactive web applications with the help of XML, HTML, CSS, and Java Script.

Question 36

What are the Xml Http Request methods?

Answer 36

- New XMLHttpRequest() - creates a new XMLHttpRequest object. - abort() - cancels the current request. - getAllResponseHeaders() - returns header information. - getResponseHeader() - returns specific header information. - open(method, url, async, user, psw) - specifies a request. - send()/send(string) - sends the request to the server. - setRequestHeader() - adds a label/value pair to the header to be sent.

Question 37

What are the Ready States in HTTP?

Answer 37

0: request not initialized 1: server connection established 2: request received 3: processing request 4: request finished and response is ready

Question 38

What are the HTTP Methods?

Answer 38

GET - requests a representation of the specified resource. Get should only be used to get data. HEAD - asks for a response identical to that of a GET request, but without the response body. POST - used to submit an entity to the specified resource, often causing a change in state or side effects on the server. PUT - replaces all current representations of the target resource with the request payload. DELETE - deletes the specified resource. CONNECT - establishes a tunnel to the server identified by the target resource. OPTIONS - used to describe the communication options for the target resource. TRACE - performs a message loop-back test along the path to the target resource. PATCH - used to apply partial modifications to a resource.

Question 39

What is the AJAX workflow?

Answer 39

``` Step 1: initialize the XMLHttpRequest() Step 2: create the onreadstatechange funciton Step 3: open the request GET/POST, “url”, true/false Step 4: send the request ```