Deck 10: Loops, Additional Controls, Manipulating Css With Javascript

Question 1

The following code retrieves the radio button collection for a group of radio buttons where "ethnicity" is the name of the radio button group:
EthnicityRBs = form.elements["ethnicity"];
How can you retrieve the selected radio button's value?

A) ethnicityRBs.selection
B) ethnicityRBs.value
C) ethnicityRBs.getValue(0)

Answer 1

B

Question 2

Suppose birthYears is the name of a pull-down menu control. What happens when the following code executes?
BirthYears.selectedIndex = 0;

A) The pull-down menu expands to show all the menu's options.
B) The pull-down menu displays "invalid."
C) The browser engine selects the pull-down menu's first option.

Answer 2

C

Question 3

In executing a while loop, the JavaScript engine first executes the while loop's body and then checks the while loop's condition.

Answer 3

False

Question 4

To create a group of checkboxes, you should use the same id attribute value for each checkbox in the group.

Question 5

You should have a prologue in your JavaScript external files. What is a prologue?

Question 6

There are two techniques for connecting a label element to its control: (1) using a for attribute, and (2) embedding the control inside the label element's start and end tags. What is the difference in functionality between these two techniques?

Question 7

What is the purpose of the z-index CSS property?

Question 8

When executed, what does the following code fragment display?
var x = 5;
var y = x++;
alert("x = " + ++x + ", y = " + y);

Question 9

Is the readonly keyword an HTML attribute or a JavaScript property?

Question 10

To implement a pull-down menu, you provide a select container with a list of elements inside it. Those elements form the selections for the menu. What is the element type for those elements?

Question 11

Which of the following is a list of JavaScript data types?

A) 22, "honey badger", true
B) number, string, object, Boolean
C) <code>num, name, employee, userTurn</code>

Question 12

Proper coding conventions suggest using <code>let</code> instead of <code>var</code> for the for loop's index variable because:

A) the <code>let</code> keyword automatically initializes the index variable to 0.
B) the <code>let</code> keyword limits the scope of the index variable to the <code>for</code> loop.
C) the <code>var</code> keyword is not part of the HTML5 standard (although many browsers still support it).

Question 13

For the textarea control, how do you specify the textarea control's default user input?

A) The browser displays the content between the <code>textarea</code> element's start and end tags.
B) The browser uses the <code>textarea</code> tag's value attribute and displays its value.
C) The browser uses the <code>textarea</code> tag's default attribute and displays its value.

Question 14

If a pull-down menu's <code>select</code> element has a <code>required</code> attribute, it means that when the pull-down menu's form is submitted:

A) the pull-down menu expands to show all the menu's options.
B) the browser highlights the pull-down menu, usually with a red border.
C) the pull-down menu control is considered to be invalid if the user's selected value is the empty string.

Question 15

The number of times that a loop repeats is referred to as the number of loop iterations.

Question 16

Applying the <code>display: flex</code> property-value pair to a container causes the container to expand beyond the browser window's borders.

Question 17

The textarea control's <code>maxlength</code> attribute specifies the maximum number of characters the user can enter into the textarea's box.

Question 18

In a pull-down menu, if no <code>option</code> element has a <code>selected</code> attribute, then the pull-down menu displays "invalid" by default.

Question 19

The length of time that a variable's value survives before it is wiped out is known as a variable's __________.

Question 20

For the textarea control, the ______ attribute specifies the textarea control's height, which is the number of lines of text in the box that can be viewed simultaneously.

Question 21

What happens if you include a multiple attribute with a select element, but do not include a size attribute?

A) The browser displays a pull-down menu with multiple copies of the specified option element.
B) The browser displays a pull-down menu where multiple options can be selected by expanding the pull-down menu multiple times.
C) The browser displays a list box with a default size of 4 (four selections appear simultaneously within the list box).

Question 22

What is an advantage of a list box as compared to a pull-down menu?

A) List boxes can be configured so they allow users to select more than one option.
B) List boxes take up less space.
C) With list boxes, each option has a button at its left.

Question 23

To process a user's selections from a list box, use the select element object's selectedOptions property to access the selected options and loop through those selected options.

Question 24

Local variables persist only for as long as the JavaScript engine is executing code within the variable's function.

Question 25

To make a border around a group of controls, surround the control elements with a legend container. To make a caption for the group, include a fieldset element within the legend container.

Question 26

Every web page element object has a style property, and that style property is an object that has properties for the web page element object's CSS properties.

Question 27

If you include the __________ attribute with a select element, the user will be able to select multiple options.

Question 28

If a pull-down menu's option element has a(n) __________ attribute, the option's value is preselected within the pull-down menu.

Question 29

Suppose you have a collection of checkboxes named skills. To access an individual checkbox within the collection, you can use skills[i]. The i is referred to as a(n) ______ variable.