web dev exam 5

which function does not display a dialogue box? window.open, window.prompt, window.alert, window.confirm

window.open

how many parent and child elements does the ol element have?

1 parent, 3 children

what is the only node that does not have a parent?

html node

What call is equivalent to document.getElementById("abc")?

document.querySelector(“#abc”);

What is missing to change "Hello!" to "Hola!"?

para.innerHTML(if you want to use tags like bold or ul) or para.textContent (would just print out <em> as apposed to applying emphasis - considered to be safer from hackers)

The code.js file contains a function called doSomething(). What happens when the browser processes the script tags?

code.js downloads first, then doSomething() is called

What is assigned to para?

null

What is missing to replace all paragraphs' text with "TEST"?

paras[i].textContent=”TEST”;

What code is missing to change cat.jpg to dog.jpg?

img.src=”dog.jpg”;

The DOMContentLoaded event occurs when _____.

all the HTML in the webpage has been processed

Which event occurs when the user changes the value of an input widget?

input

Which call correctly adds a click event handler to the button?

btn.addEventListener(“click”, sayHello);

window.alert()

displays dialog box with a message and ok button

window.confirm()

displays dialog box with OK and Cancel, returns bool

window.prompt()

displays dialog box with message and input field, returns null if user cancels

window.open()

opens new browser window with specified URL

async attribute

script is executed as soon as it’s downloaded, before entire HTML is parsed

defer attribute

used more often, waits until entire HTML doc is parsed

code minification

reduces unnecessary characters to reduce file size - takes out comments, line breaks, etc

code obfusication

makes code hard to read

how to use input

<input type="button" value="Click Me" id="mybutton">

how do you modify a node’s attribute?

node.attribute = “value”;

how do you remove an attribute in JavaScript

node.removeAttribute(“attribute”);

textContent vs innerHTML

textContent retrieves or sets the plain text of a node, innerHTML retrieves or sets the HTML markup within a node

how to get value of a textbox from input

document.getElementById("id").value

What does setTimeout() do in JavaScript?

setTimeout(eventHandler, millisecs) executes a function after a specified delay (in milliseconds).

What does clearTimeout() do in JavaScript?

clearTimeout(timerId) stops a timeout that was previously set using setTimeout()

What does setInterval() do in JavaScript?

setInterval(eventHandler, millisecs) repeatedly executes a function at a specified interval (in milliseconds).

What does clearInterval() do in JavaScript?

clearInterval(timerId) stops a repeated interval that was previously set using setInterval().