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)

Accepted Answer

The correct way to retrieve the selected radio button's value is by iterating through the radio button collection and checking which one is checked, then accessing its value property. However, if you want a direct property, `ethnicityRBs.value` is the closest, but it may not work directly without iteration.

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.

Accepted Answer

The code sets the selectedIndex property of the pull-down menu to 0, which selects the first option in the menu.

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.

Accepted Answer

In a while loop, the JavaScript engine first checks the condition before executing the loop's body. If the condition is true, the body is executed; otherwise, the loop terminates.

Question 4

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

Accepted Answer

The id attribute must be unique within a page. To group checkboxes, use the same name attribute instead.

Question 5

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

Accepted Answer

The answer of You should have a prologue in your...

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?

Accepted Answer

The answer of There are two techniques for connecting a...

Question 7

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

Accepted Answer

The answer of What is the purpose of the z-index...

Question 8

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

Accepted Answer

The answer of When executed, what does the following code...

Question 9

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

Accepted Answer

The answer of Is the readonly keyword an HTML attribute...

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?

Accepted Answer

The answer of To implement a pull-down menu, you provide...

Question 11

Which of the following is a list of JavaScript data types? A) 22, "honey badger", true B) number, string, object, Boolean C) num, name, employee, userTurn

Accepted Answer

JavaScript data types include number, string, object, and Boolean.

Question 12

Proper coding conventions suggest using let instead of var for the for loop's index variable because: A) the let keyword automatically initializes the index variable to 0. B) the let keyword limits the scope of the index variable to the for loop. C) the var keyword is not part of the HTML5 standard (although many browsers still support it).

Accepted Answer

The `let` keyword limits the scope of the index variable to the `for` loop, preventing potential issues with variable scope outside the loop.

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 textarea element's start and end tags. B) The browser uses the textarea tag's value attribute and displays its value. C) The browser uses the textarea tag's default attribute and displays its value.

Accepted Answer

The default user input for a textarea is specified by placing the content between the <textarea> element's start and end tags.

Question 14

If a pull-down menu's select element has a required 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.

Accepted Answer

The `required` attribute ensures that the user selects a non-empty option before form submission, making the control invalid if the selected value is empty.

Question 15

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

Accepted Answer

The term "loop iterations" refers to the number of times a loop executes its block of code.

Question 16

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

Accepted Answer

The `display: flex` property-value pair is used to create a flexible layout within a container, but it does not inherently cause the container to expand beyond the browser window's borders. It simply changes how the container's children are arranged.

Question 17

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

Accepted Answer

The `maxlength` attribute in a textarea element limits the number of characters a user can input, ensuring the input does not exceed the specified length.

Question 18

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

Accepted Answer

If no option is selected, the first option in the list is displayed by default, not "invalid".

Question 19

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

Accepted Answer

The answer of The length of time that 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.

Accepted Answer

The answer of For the textarea control, the ______ attribute...

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

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?

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

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

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

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

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?

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

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

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

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?

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

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

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

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:

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

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

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

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.

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

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.