Thẻ ghi nhớ: Interactivity with JavaScript - Week 3 Quiz | Quizlet

Arrays can store multiple, related pieces of information.

True

False

True

Array indexes start with 0. [0] is the first element. [1] is the second element, etc.

True

False

True

Arrays can store multiple, related pieces of information, but they must all be of the same type (String, Object, etc.).

True

False

False

Which is the proper way to declare an array?

var grades= (80, 87, 94, 82, 62, 98, 81, 81, 74, 91)

var grades= [80, 87, 94, 82, 62, 98, 81, 81, 74, 91]

array grades= [80, 87, 94, 82, 62, 98, 81, 81, 74, 91]

grades= Array(80, 87, 94, 82, 62, 98, 81, 81, 74, 91)

var grades= [80, 87, 94, 82, 62, 98, 81, 81, 74, 91]

Every index in an array must be a numeric value.

True

False

True

Elements are referenced by index.

True

False

True

In JavaScript the first index in an array is 0.

True

False

True

What is the value of the element in position 4?

12 45 32 56 1 12 10

1

What is the index of the element with the value of 10?

12 45 10 56 1 14 12

2

var my_array = [2, 4, 6, 8, 10]

What is the value of my_array[2] ?

2

4

6

8

10

Undefined

6

var my_array = [2, 4, 6, 8, 10]

What is the value of my_array.length ?

5

4

Undefined

5

JavaScript Arrays have attributes and methods.

True

False

True

When declaring an array Spaces and line breaks are important. A declaration can not span multiple lines.

True

False

False

Which of these is not valid? (Hint, pay attention to if the method should return one thing, or many things...)

var my_array = document.getElementsByTagName(tagName)

first_element = my_array[0]

var my_array = document.getElementsByClassName(className)

first_element = my_array[0]

var my_array = document.querySelector(#idName)

first_element = my_array[0]

var my_array = document.querySelector(#idName)

If your browser supports debugging, you can use which of the following to display JavaScript values in the debugger window:

console.debug

document.log

document.debug

console.log

console.log

How do you properly access the third element in an array variable named "fruit"?

[fruit]3

fruit[3]

fruit_3

None of the above

fruit[3]