MCQs (JavaScripting)

JavaScript was created by Google in 2005 for the Gmail application that needed more interactivity

1. No, JavaScript was invented in 1995 by Netscape Corp.
2. Yes, Google proposed an open implementation of the language in 2003 to ECMA

var x = 34;
var y = 10;
var z = x%y;
What value is stored in the variable z after the following lines of code are executed?

1. 2
2. 4
3. 5
4. 3

Which of the following are used to create a variable and assign it a value?

1. data type and identifier
2. identifier and a value
3. value and an assignment operator (=)
4. data type, identifier, value and an assignment operator (=)

Which of the following statements calls a function, giveMeANumber, and passes the number 4 as a parameter?

1. giveMeANumber();
2. giveMeANumber().4;
3. giveMeANumber(4);
4. giveMeANumber(==4);

var language = "JavaScript";
The data type of the language variable above is:

1. number
2. string
3. boolean
4. double

typeof "390"
What is the result of the this statement?

1. boolean
2. number
3. string
4. object

Consider the following code:
var x = 2;
var y = 6;
var z = -3;
Which of the following line of code will update the stored value of the variable y to 3?

1. y = x
2. y /= 2;
3. y = z
4. y == 3

Which of the following statements changes the CSS background-color of an element to "green"?

1. element.background-color = "green";
2. element.style.backgroundColor = "green";
3. element.style.background-color = "green";
4. element.set("background-color", "green");

Which of the following statements declares a variable named score?

1. score;
2. variable score;
3. var score;
4. declare var score;

Which message will be displayed on the document when the following code is executed?
var num = 24;
if(num > 82)
{
document.write("zone 1");
}
else if(num >= 43)
{
document.write("zone 2");
}
else{
document.write("zone 3");
}

1. zone 1
2. zone 2
3. zone 3
4. none of the given

JavaScript can only run in a browser (It cannot run in other environments).

1. True
2. False

Consider the code:
var greeting = "Hello";

var contact = {
firstName: "Jane",
lastName: "Doe",
age: 35
};
What line of code update the greeting variable to store the value "Hello Jane"?

1. greeting += firstName;
2. greeting += contact.firstName;
3. greeting += " " + contact.firstName;
4. greeting = greeting + " " + contact.lastName;

Which of the following statements invokes a function named myFunction that accepts a numeric parameter?

1. myFunction 4;
2. myFunction(4);
3. myFunction <-(4);
4. myFunction[4];

What will the value of x be when the following while loop stops executing?
var x = 4;
while(x > 0)
{
alert("Hello ");
x--;
}

1. 4
2. 0
3. 1
4. this is an infinite loop- will never stop executing

Which alert message(s) will be displayed when the following code runs?
var num = 42;

if(num <= 30)
{
document.write("Alert message #1");
}
else{
document.write("Alert message #2");
}

1. "Alert message #1"
2. "Alert message #2"
3. Neither
4. Both

typeof "-34.7"

1. number
2. string
3. boolean

Which of the following statements defines a function named increment that returns a value and defines a parameter?

1. increment(num){
   num++;}
   return num;
2. increment(num){
   num++;
   return num;}
3. function increment(num){
   num++;
   return num;}
4. func increment(num){
   param: num;
   num++;
   return (num);}

In order to write JavaScript code that is embedded in an HTML file, your JavaScript code belongs ________.

1. at the top of the HTML file
2. within a script element
3. within a javascript element
4. at the end of the HTML file

Which of the following does not output information to the user via the webpage?

1. window.alert
2. console.log
3. document.write
4. element.innerHTML

typeof "Hello, world"

1. number
2. string
3. boolean

var x = 25;
var y = 12;
var z = x < y;
What value is stored in the variable z above?

1. true
2. false
3. 12
4. 25

Consider the following object:
var book = {
title: "Romeo and Juliet",
author: "William Shakespeare",
publishDate: 1597
};
Considering the book object above,
author is a ________ of the book object.

1. value
2. property
3. object
4. data type

Which of the following statement sets a function called myHandler to be called when myButton is clicked?

1. myButton.onclick = myHandler;
2. myButton.click = myHandler;
3. myButton.addEventListener("onClick", myHandler);

A ________ is a container that can store a value in your program that can be accessed or modified at a later point.

1. temp
2. block
3. variable
4. segment

Which alert message(s) will be displayed when the following code runs?
var num = 35;
if(num <= 30) {
document.write("Alert message #1");
}
else{
document.write("Alert message #2");
}

1. "Alert message #1"
2. "Alert message #2"
3. Neither
4. Both

Assume that a variable has been declared and initialized with the following statement:
var count = 4;
Which of the following statements updates the variable with the value 24?

1. var count = 24;
2. update count 24;
3. count == 24;
4. count = 24;

Which of the following statements stores a value returned from a function?

1. var value = myFunction;
2. var value = myFunction();
3. myFunction -> var value;
4. var value = return myFunction;

Which of the following statements changes the href attribute of an element to "www.microsoft.com"?

1. element.sethref("www.microsoft.com");
2. element.attribute.href = "www.microsoft.com";
3. element.setAttribute("href", "www.microsoft.com");
4. element.href("www.microsoft.com");

Consider the following object:
var book = {
title: "Romeo and Juliet",
author: "William Shakespeare",
publishDate: 1597
};
Considering the book object above,
which line of code will write the publish date of the book object to the browser console?

1. console.log(book.publishDate);
2. console.log(book.author);
3. console.log(publishDate);
4. console.log(book.title);

var x = 4;
var y = 9;
var z = x < y;
What value is stored in the variable z above?

1. 4
2. 9
3. true
4. false

Which of the following statements invokes a function named myFunction that has no parameters?

1. myFunction;
2. myFunction();
3. myFunction[];
4. myFunction!

What value is stored in the variable x after the following lines of code are executed?
var x = 3;
x*=2;

1. 2
2. 3
3. 6
4. 9

var x = 4;
var y = 9;
var z = x < y;
What is the data type of the variable z above?

1. boolean
2. number
3. string
4. double

Consider the following code:
var x = 2;
var y = 6;
var z = -3;
Which of the following line of code will update the stored value of the variable y to 3?

1. y = x
2. y = y/x;
3. y = z
4. y == 3

JavaScript statements end with ________.

1. a semicolon (;)
2. forward slashes (//)
3. back slashes (\\)
4. a period (.)

What causes a loop to be infinite?

1. It does not include a statement that modifies the test/condition.
2. It does not include a closing brace
3. It does not have a return statement
4. It does not have a proper condition

What belongs immediately after the if keyword in an if statement, within the parentheses?
if ( )

1. An else statement
2. A return statement
3. A condition
4. A number

A JavaScript variable that originally stored a number can later store a string value.

1. True
2. False

Which of the following statement sets a function called myHandler to be called when myButton is clicked?

1. myButton.click = myHandler;
2. myButton.addEventListener("onClick", myHandler);
3. myButton.addEventListener("click", myHandler);

What is the result of the following statement?
typeof 340.2

1. decimal
2. number
3. string
4. object

typeof -34.7

1. number
2. string
3. boolean

Which message will be displayed on the document when the following code is executed?
var num = 40;
if(num > 60) {
document.write("zone 1");
}
else if(num > 25) {
document.write("zone 2");
}
else{
document.write("zone 3");
}

1. zone 1
2. zone 2
3. zone 3
4. none of the above

What value is stored in the variable x after the following lines of code are executed?
var x = 9;
var y = 3;
var z = x%y;

1. 0
2. 1
3. 2
4. 3

In JavaScript, in order to change the content of an HTML document or the CSS style of HTML elements, we use:

1. The selector and the DOM API
2. The HTML API
3. The CSS API
4. None of the given.

Consider the following code:
var book = {
title: "Romeo and Juliet",
authorFirstName: "William",
authorLastName: "Shakespeare",
publishDate: 1597
};
The code above creates a(n) ________ with the identifier book.

1. property
2. object
3. value
4. data type

Which of the following for-loop declarations creates a loop that will execute 4 times?

1. for(x = 1; x < 4; x++)
2. for(x = 0; x < 4; x++)
3. for(x = 1; x < 3; x++)
4. for(x = 0; x < 5; x++)

What is the primary role of JavaScript?

1. To translate Java for webpages
2. To style web content
3. To add dynamic behavior to webpages
4. To store and retrieve data from databases

How can a function return a value?

1. return the value in the body of the function with the return keyword
2. include a return statement after the body of the function
3. include the return keyword in the parameter list( ) use the function return (parameter1, parameter2) syntax
4. none of the given

Which message will be displayed on the document when the following code is executed?
var x = 3;
var y = 8;
if(x % 2 == 1 && y > 6)
{
document.write("This test passed" );
}
else{
document.write("This test failed");
}

1. This test passed
2. This test failed
3. Neither message will be displayed
4. Both messages will be displayed

Consider the following code:
var x = 2;
var y = 6;
var z = -3;
Which of the following line of code will update the stored value of the variable y to 3?

1. y = x
2. y = -z;
3. y = z
4. y == 3

Which JavaScript statement creates a new list item element and stores it in a new variable named listItem.

1. var listitem = document.createElement('ul');
2. var listitem = document.createElement('li');
3. var listitem = document.createElement('ol');
4. var listitem = document.Element('li');

Which of these is a JavaScript array?

1. var c = 10;
2. var a = ['sin', 'cos', 'tan'];
3. var b = {min:-1, max:1};
4. All of the given

Consider the following code:
var book = {
title: "Romeo and Juliet",
authorFirstName: "William",
authorLastName: "Shakespeare",
publishDate: 1597
};
What line of code logs the value of the title property to the console?

1. console.log(book.authorLastName);
2. console.log(book.authorFirstName);
3. console.log(book.title);
4. console.log(book.publishDate);

What is an infinite loop?

1. A loop that contains many lines of code
2. A loop that never stops iterating
3. A loop that doesn't have a return statement
4. A loop that doesn't have a closing brace

Which message will be displayed on the document when the following code is executed?
var x = 3;
var y = 8;
if(x < 5 && y > 6) {
document.write("This test passed");
}
else{
document.write("This test failed");
}

1. This test passed
2. This test failed
3. Neither message will be displayed
4. Both messages will be displayed

Which of the following for-loop declarations creates a loop that will execute 4 times?

1. for(x = 1; x < 4; x++)
2. for(x = 1; x < 5; x++)
3. for(x = 1; x < 3; x++)
4. for(x = 0; x < 5; x++)

var mySection = document.getElementById("mySection");
var special = mySection.getElementsByClassName("special");
What will the variable special contain after this code is executed?

1. A collection of all elements that have the class "special"
2. The first element in the document with the class "special"
3. A collection of all elements with the class "special" that are children of the element with the id "mySection"
4. A collection of all elements that are children of the element with the id "mySection"

Which statement retrieves the element "d" from the array myArray?
var myArray = ["a", "b", "c", "d", "e"];

1. myArray["d"]
2. myArray[4]
3. myArray[3]
4. myArray.getElement(4)

Which of the following statements declares a (non-global) variable named myNum and assigns it a value of 24?

1. myNum = 24;
2. variable myNum set to 24;
3. num myNum 24;
4. var myNum = 24;

Which of the following keywords is used to define a function?

1. function
2. func
3. new
4. method

JavaScript is a(n) ________.

1. isolated language
2. Java variant
3. scripting language
4. compiled language

A JavaScript script will always be executed after the HTML page finishes loading.

1. True
2. False

A complete line of JavaScript code that can be executed by the computer is called a(n) ________.

1. block
2. statement
3. executable
4. variable

A(n) ________ can hold a collection of named values, known as properties.

1. data type
2. object
3. property
4. temp

Which of the following can be used to modify the text within a paragraph?

1. element.displayText
2. document.write
3. element.write
4. element.innerHTML

Consider the variable:
var greeting = "Hello";
greeting += "John";
What value is stored in the greeting variable after the 2nd line of code?

1. "Hello John"
2. HelloJohn
3. "John"
4. "HelloJohn"

What output will be displayed on the document when the following loop completes?
for(x = 0; x < 4; x++){
document.write(x + " ");
}

1. x x x x
2. 0 1 2 3
3. 0 1 2 3 4
4. x x x x x

Which line of code creates a variable named language that holds that value "JavaScript"?

1. variable language: "JavaScript";
2. var language: JavaScript;
3. var language = JavaScript;
4. var language = "JavaScript";

Which statement retrieves the element with the value 32 from the array numbers?
var numbers = [1, 3, 12, 42, 32, 4];

1. numbers.get(32)
2. numbers[32]
3. numbers[4]
4. numbers[5]

JavaScript allows you to develop webpages that are ________. This means the webpage's content changes based on conditions and interactions.

1. static
2. dynamic
3. encapsulated
4. inherited

Consider the following code:
var x = 2;
var y = 6;
var z = -3;
What is the datatype of the variable **z**?

1. number
2. negative
3. int
4. whole

Which of the following statement would return a collection of elements that have the class "special"?

1. document.getElementByTagName("special");
2. document.querySelector(".special");
3. document.getClass(".special");
4. document.querySelectorAll(".special");

Which statement creates an array named colors and stores 4 elements?

1. var colors = ["red", "orange", "yellow", "green"];
2. var colors = array["red", "orange", "yellow", "green"];
3. var colors = new array("red", "orange", "yellow", "green");
4. var colors = array: ["red", "orange", "yellow", "green"];

Which JavaScript statement creates a new list item element and stores it in a new variable named listItem?

1. var listitem = document.getElement("li");
2. var listitem = document.createElement.li;
3. var listitem = document.createElement("li");
4. var listitem.document.createElement("li");

Which of the following lines of code produces the value "William Shakespeare"?

1. book.authorFirstName + book.authorLastName
2. book.authorFirstName.authorLastName
3. book.authorFirstName + " " + book.authorLastName
4. book{authorFirstName+authorLastName}

Which JavaScript statement uses the document object to get a list of all of the h1 elements on a page and stores the collection in a variable named headings.

1. var headings = document.getElementById("h1");
2. var headings = document.getElementsByTagName("h1");
3. var headings = document.getElementBySelector("h1");
4. var headings = document.getElementsByClassName("h1");

Which of the following statements declares a variable named highScore?

1. new var highScore;
2. variable highScore;
3. var highScore;
4. declare var highScore;

var myVar = "23";
What is the data type of the variable myVar?

1. number
2. string
3. boolean
4. double

Consider the code:
var greeting = "Hello";

var contact = {
firstName: "Jane",
lastName: "Doe",
age: 35
};
What line of code update the greeting variable to store the value "Hello Jane"?

1. greeting += firstName;
2. greeting += contact.firstName;
3. greeting = greeting + " " + contact.firstName;
4. greeting = greeting + " " + contact.lastName;

JavaScript code is case sensitive.

1. True
2. False

Which of the following statement would return a collection of elements that have the class "special"?

1. document.getElementsByClassName("special");
2. document.querySelector(".special");
3. document.getClass(".special");
4. document.getElementByTagName("special");

var x = 25;
var y = 12;
var z = x < y;
What is the data type of the variable z above?

1. string
2. number
3. boolean
4. object