JavaScript Quiz - After Hours Programming

The JavaScript practice quiz is designed to quiz how well you understand JavaScript. The quiz primarily focuses on DOM manipulation, but covers the fundamentals of JavaScript. After completing the practice quiz, feel free to move on to server side programming languages.

1. What is the symbol(s) to comment out one line in JavaScript?

//This is a comment

**This is a comment

%% This is a comment

** This is a comment **

2. How do you create a variable x that is equal to the string “Hello”?

string x = “Hello”;

var x = “Hello”;

text x = “Hello”;

strings x = “Hello”;

3. How do you create a variable x that is equal to the integer 4?

int x = 4;

num x = 4;

var x = 4;

number x = 4;

4. If the variable x is already defined and equals 4. Now, if the statement is “document.write(x++);”, what would be displayed in the browser?

5. If x equals 7, and the only other statement is x = x % 3, what would be the new value of x?

6. Which of the following is not a comparison operator used in an if statement?

7. What is the keyword inside of a switch statement to create a condition?

case

condition

else

8. What is the keyword to define a function in JavaScript?

def

func

function

none of the above

9. Which of the following is an acceptable declaration of a for loop?

for(var i = 0; i < 5; i++)

for(var i = 0, i < 5)

for(i < 5)

for(var i = 0, i < 5, i++)

10. In a do while loop, which of the following is correct?

The do statement is only executed if the while statement is correct.

The while statement precedes the do statement.

The do statement might not always be executed.

The do statement is always run at least once.

11. What two statements can you use in your JavaScript to handle errors?

try/except

try/catch

attempt/except

attempt/catch

12. What statement can you use to completely exit a loop and continue on through your code?

break

exit

continue

forward

13. What statement can you use to exit the current iteration of the loop, where if the condition is still satisfied, you would proceed through the next loop?

break

exit

continue

forward

14. In the string variable ‘I’m awesome’, would throw an error. Which of the following is a correct way to correct this problem?

‘I’m awesome’

“I’m awesome”

15. What is a correct way to get an HTML element by its id?

document.getElementsByID

document.getElementsById

document.getElementByID

document.getElementById

16. What is the correct way to get an HTML element by its name?

document.getElementByName

document.getElementsByName

document.getElementsByElementName

document.getElementByElementName

17. How would you get the number of characters in the string variable example?

example.length

example.count

example.len

example.number

18. How would you break up a string variable, example, into separate characters?

example.split(”)

example.break()

example.substr()

example.toSplitArray()

19. In JavaScript, how to you convert a string to lower case?

example.toLowerCase()

example.lowerCase()

example.toLower()

example.lower()

20. In a JavaScript regular expressions, what does ‘/g’ mean?

The expression is not case sensitive.

The expression returns all matches.

The expression will match multiple lines.

The expression will return the first value only.

21. How do you create an array in JavaScript?

var example = (‘aa’, ‘bb’);

var example = array(‘aa’, ‘bb’);

var example = new Array (‘aa’, ‘bb’);

var example = new array (‘aa’, ‘bb’);

22. How would you create a new date object in JavaScript?

var d = (2012, 3, 1, 20, 28, 56, 445);

var d = date(2012, 3, 1, 20, 28, 56, 445);

var d = new date(2012, 3, 1, 20, 28, 56, 445);

var d = new Date(2012, 3, 1, 20, 28, 56, 445);

23. How would you round up a number with a decimal to the nearest integer?

Math.roundUp(x);

Math.ceil(x);

x.roundUp();

x.ceil(x);

24. Internal JavaScript code is encased in what tag?