js2

Question 1

Javascript: In the javascript console, to return the html of the current page that has a certain css id, type

Answer 1

document.getElementById(“cssid”)

Question 2

Javascript: In the javascript console, to return just the first html element of the current page that has any css selector, type

Answer 2

document.querySelector(“.css-selector”)

Question 3

javascript: To return an array of all of the html tags of the body of a page, type

Answer 3

document.body.children

Question 4

javascript: To return an array of all of the html tags on a page with a certain class name, type

Answer 4

document.getElementByClassName(“class”)

Question 5

javascript: To go to a different url, type

Answer 5

window.location.replace(“http://www.google.com”);

Question 6

javascript: To return the url (including query string) of the current page, type

Answer 6

window.location.href

Question 7

javascript: to slice a string, type

Answer 7

string_var.slice(1,5);

Question 8

javascript: To return the index of a string, type

Answer 8

string_var.indexOf(“substring”);

Question 9

javascript: To return the query string (including the “?”), type

Answer 9

window.location.search

Question 10

javascript: To set a cookie on the browser, type

Answer 10

document.cookie=”key=a value; expires=Thu, 01 Jan 2016 12:00:00 UTC; path=/”;

Question 11

javascript: To delete a cookie

Answer 11

update it with an expiration date that is in the past.

Question 12

javascript: To return the cookies on the browser, type

Answer 12

document.cookie;

Question 13

javascript: To change the html that is within an element, type

Answer 13

document.getElementById(“id”).innerHTML = “new html”

Question 14

javascript: At the end of if statements. do not put

Answer 14

semicolon

Question 15

javascript: To use two conditional statements, use

Answer 15

double ampersand

Question 16

javascript: To write code that will only execute after a set amount of time, type

Answer 16

setTimeout(function(){
console.log(“string”)
}, 2000);

note: this is 2 seconds

Question 17

javascript: When you use window.location.replace(“http://url.com”)

Answer 17

it does not let the user return to the original page

Question 18

javascript: To reload a window, type

Answer 18

window.location.reload();

Question 19

node: you can access value one in var jsonObject = {key1: “value1”} by typing

Answer 19

jsonObject.key1

Question 20

node: To import a file in the same directory, type

Answer 20

var myFile = require(“./myFile”)

nore: the ./ path is mandatory

Question 21

node: To expose a function to people importing your file, type

Answer 21

module.exports.exposedFunctionName = localFunctionName;

Question 22

javascript: To create an object using a constructor function, type

Answer 22

function ConstructorFunc(param1) {
  this.attribute1 = param1;
  this.functionName = function() { console.log("string") }
}

Question 23

javascript: To instantiate an object made by a constructor function, type

Answer 23

var myInstance = new ConstructorFunc(“param1”)

Question 24

javascript: To turn a function call into a constructor function you must

Answer 24

precede the function name with "new"
e.g.
var myInstance = new ConstructorFunc("param1", "param2")

Question 25

javascript: By convention for constructor functions, people

Answer 25

capitalize the first letter

Question 26

javascript: The DOM is

Answer 26

the javascript representation of the page

Question 27

javascript: To add a function to a constructor function that does not reload every time the constructor function is instantiated, use

Answer 27

ConstructorFuncName.prototype.functionName = function() { return "string" }

Question 28

javascript: To evaluate the key name in a json object, type

Answer 28

{ [varName]: "value" }

Question 29

javascript: To run an anonymous function

Answer 29

surround it with parentheses

Question 30

javascript: To set the html of the body tag to a string, type

Answer 30

document.getElementsByTagName("body")[0].innerHTML = "script"

Question 31

javascript: The "document" object is contained in

Answer 31

the "window" object

Question 32

javascript: The "window" object contains

Answer 32

the url and the document, etc.

Question 33

javascript: The "window" object is

Answer 33

the global scope of your javascript, and contains any variables and methods you added

Question 34

javascript: To automatically return an array of all the images in the document, type

Answer 34

window.document.images

Question 35

javascript: To automatically return an array of all the scripts in the document, type

Answer 35

window.document.scripts

Question 36

javascript: To automatically return an array of all the forms in the document, type

Answer 36

window.document.forms

Question 37

javascript: a node is

Answer 37

an html element

Question 38

javascript: To trigger a function on click from the html, type

Answer 38

onclick="functionName('param1');"

Question 39

javascript: document.getElementsByTagName("string") returns

Answer 39

HTMLCollection, which is like an array

Question 40

javascript: To assign a function reference to a click handler, type

Answer 40

document.getElementById("css-id").onclick = functionName

Question 41

javascript: To create an html element, add an attribute to it, and then append it to the body, type

Answer 41

``` var elementName = document.createElement("tagname"); elementName.attribute = "value"; ``` window.document.getElementsByTagName("body")[0].appendChild(divName);

Question 42

javascript: In the javascript console, to return an array of all the elements on the current page that have any css selector, type

Answer 42

document.querySelectorAll(".css-class")

Question 43

javascript: To add just one css property to an element, type

Answer 43

document.querySelector(".css-class").style["property"] = "value";

Question 44

javascript: javascript does not have

Answer 44

multiline strings

Question 45

javascript: var a = a || {} is used to

Answer 45

not override existing variables. The new {} object is only assigned to "a" if the current value of "a" is falsey/undefined. If "a" already exists then it will not be overwritten and will be assigned back into itself.

Question 46

javascript: The break statement in a loop

Answer 46

stops the loop and continues the rest of the script.

Question 47

javascript: One way to preload an image is

Answer 47

``` imageInstance = new Image(10,10) imageInstance.src = "http://cdn.com" ```

Question 48

css: The difference between display: none; and visibility: hidden; is

Answer 48

display: none; does not even render the tag into the dom, which visibility: hidden; does render the tag into the dom

Question 49

js: To pass the event object into a function from the onclick attribute, type

Answer 49

onclick="functionName(event, param1)"

Question 50

A good general purpose npm library for all sorts of generators is

Answer 50

yeoman

Question 51

js: if you install a node module

Answer 51

using -g, then you do not need to specify the path when requiring?

Question 52

js: To send a text with twilio, type

Answer 52

client = require('twilio')('accountsId', 'authToken'); client.sendMessage({ to:'+972537227817', from: '+18186503041', body: 'string' }, function(err, responseData) { if (!err) { console.log(responseData.from); console.log(responseData.body); } });

Question 53

js: Prototypal inheritance is

Answer 53

like class inheritance but with an object instead of a class

Question 54

js: The attribute of an object that changes when they inherit from another object is

Answer 54

objectName.__proto__ = parentObjectName

Question 55

js: The event that fires every time a user clicks out of the text box they are in is called

Answer 55

blur

Question 56

js: To run a function when someone clicks into an input, type

Answer 56

onfocus="functionName()"

Question 57

js: The event that fires when someone clicks into an input is called

Answer 57

focus

Question 58

js: To check if a string passes a regex test, type

Answer 58

stringVar.match(/regex/i)

Question 59

js: To pass an inputs current value into an inline onclick function, type

Answer 59

onclick("functionName(this.value)")

Question 60

js: document.querySelectorAll() does not

Answer 60

return an array, so to iterate over it, put it in a var, and use a regular for () loop

Question 61

js: To remove an element, type

Answer 61

``` var elem = document.getElementById("myDiv"); elem.parentNode.removeChild(elem); ```

Question 62

js: To set and get variables from js after a page reload

Answer 62

localStorage.setItem("varName", "value"); var varName = localStorage.getItem("varName");

Question 63

js: To insert a string into the html only if javascript is disabled on a browser, type

Answer 63

-noscript>string-/noscript>

Question 64

js: To automatically submit a form after it changes, type

Answer 64

onchange="this.form.submit()"

Question 65

js: To dispatch an event with a customized event name, type

Answer 65

``` var myEvent = new Event('eventName', {bubbles: true}) document.body.dispatchEvent(myEvent) ``` Note: document.body.click() is the same as above, but the eventName is "click"