JavaScript 101

1. An identifier cannot begin with a number. Which of the following is NOT a valid identifier?

• 1identifier
• Identifier1
• _identifier
• $IDENTIFIER

2. An identifier can begin with an underscore (“_”).

• True
• False

3. An identifier can begin with a number.

• True
• False

4. In JavaScript, an identifier may begin with an underscore, a letter, or a dollar sign. Which of the following is a valid identifier? Select all that apply.

• $ident1
• _ident
• IDENT20
• 20IDENT

5. Which of the following is a valid function call?

• forward;
• forward
• forward();
• All answers are correct

6. Select the following function calls that are invalid.

• (move);
• call function move
• move;
• forward();

7. How would you call a function called “myFunction”?

• Call myFunction();
• myfunction();
• myFunction();
• call function myFunction();

8. Identifiers in JavaScript are case-sensitive.

• True
• False

9. 78090 is a valid identifier in JavaScript.

• True
• False

10. Select the statements that contain errors.

• forward();

• forward();
  forward();

• forward(();
• forward{};

11. Select the following invalid identifiers. (Identifiers are only allowed to start with a dollar sign, underscore, or letter.)

• &ident
• 1ident
• _ident
• -ident

12. How would you move an object forward 3 times?

• 

  forward();
  forward();
  forward();

• forward() * 3;
• Call_forward() 3 times;
• forward() {3};

13. You are not able to call the same function twice in a row.

• True
• False

14. You can replace the parentheses on a function call with square brackets.

• True
• False

15. The parentheses at the end of a function call are optional.

• True
• False

16. Which of the following is the correct way to start a multi-line comment?

• //
• */
• /*
• \

17. Both of the following are valid ways to comment code:

//hello 
//world

/*hello
world*/ 

• True
• False

18. Which of the following comments are correct? Select all that apply.

• 

  // hello

• 

  /* hello */

• 

  /*he
      llo */

• /*he
  llo 

19. Commented lines affect the execution of your program.

• True
• False

20. Which of the following is a correct multi-line comment?

• */ hello
  World */
  

• */ hello
  World /*
  

• 

  /* hello
  World */
  

• /*hello
  World /*
  

21. What is the error in this code?

/* 
    This function does something
*/
function foo() {
    print("hello world"); \ print a message
}

• The single line comment must use // instead of \
• The end to the multi-line comment cannot be on its own line
• The beginning and end of the multi line comments are incorrect
• All answers are errors in the code