JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 69 · 40 questions

Code tip (Line by line): let x = 5; makes a variable x holding 5; x = x + 2; changes it to 7. console.log(…) writes in the console; alert(…) shows a pop-up box. Text in quotes + anything = joined text: "5" + 3 → "53".

1. 1.⚡ What does this code print? (Look at the quotes!)
   let x = "2";
   let y = 2;
   console.log(x + y); (a) 4 (b) 22 (c) Error
2. 2.⚡ What does JavaScript add to a web page? (a) the domain name (b) only colours (c) actions and changes (d) the page title
3. 3.⚡ Where does console.log() show its output? (a) on the printer (b) in the console (c) on the title bar (d) in the address bar
4. 4.⚡ What number does this code print?
   let a = 14;
   let b = 32;
   console.log(a + b);
5. 5.⚡ What does this code print? (Look at the quotes!)
   let x = "2";
   let y = 3;
   console.log(x + y); (a) Error (b) 5 (c) 23
6. 6.⚡ What does this code show?
   let name = "Zoya";
   console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) name (c) Zoya (d) Welcome, Zoya!
7. 7.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <js> (c) <script> (d) <style>
8. 8.⚡ What does this code print? (Look at the quotes!)
   let x = "7";
   let y = 4;
   console.log(x + y); (a) 74 (b) 11 (c) Error
9. 9.⚡ What does this code show?
   let name = "Riya";
   alert("Welcome, " + name + "!"); (a) Welcome, name! (b) name (c) Riya (d) Welcome, Riya!
10. 10.⚡ Which JavaScript word runs code when true? (a) console.log() (b) let (c) if (d) alert()
11. 11.⚡ What does this code show?
    let name = "Aman";
    alert("Hi, " + name + "!"); (a) Hi, name! (b) Aman (c) name (d) Hi, Aman!
12. 12.⚡ What number does this code print?
    let coins = 26;
    coins = coins + 4;
    coins = coins - 13;
    console.log(coins);
13. 13.⚡ A JavaScript file usually ends with which extension? (a) .jpg (b) .js (c) .html (d) .css
14. 14.⚡ What number does this code print?
    let a = 3;
    let b = 9;
    console.log(a * b);
15. 15.⚡ Which JavaScript word repeats code? (a) console.log() (b) alert() (c) let (d) for
16. 16.⚡ What number does this code print?
    let a = 5;
    let b = 9;
    console.log(a * b);
17. 17.⚡ Which JavaScript word writes in the console? (a) let (b) if (c) console.log() (d) alert()
18. 18.⚡ What number does this code print?
    let a = 2;
    let b = 7;
    console.log(a * b);
19. 19.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 3;
    console.log(x + y); (a) 73 (b) 10 (c) Error
20. 20.⚡ What does this code show?
    let name = "Aman";
    alert("Well done, " + name + "!"); (a) Aman (b) name (c) Well done, Aman! (d) Well done, name!
21. 21.⚡ What number does this code print?
    let a = 23;
    let b = 27;
    console.log(a + b);
22. 22.⚡ Which JavaScript word shows a pop-up box? (a) for (b) if (c) alert() (d) let
23. 23.⚡ What number does this code print?
    let a = 12;
    let b = 3;
    console.log(a * b);
24. 24.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 3;
    console.log(x + y); (a) 8 (b) Error (c) 53
25. 25.⚡ Which JavaScript word makes a new variable? (a) console.log() (b) for (c) if (d) let
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 1;
    console.log(x + y); (a) 81 (b) 9 (c) Error
27. 27.⚡ What number does this code print?
    let a = 4;
    let b = 6;
    console.log(a * b);
28. 28.⚡ What does alert() show? (a) a pop-up box (b) a new tab (c) a table (d) a picture
29. 29.⚡ What number does this code print?
    let marks = 7;
    marks = marks + 18;
    marks = marks - 5;
    console.log(marks);
30. 30.⚡ What does this code show?
    let name = "Arjun";
    console.log("Well done, " + name + "!"); (a) name (b) Well done, Arjun! (c) Arjun (d) Well done, name!
31. 31.⚡ What number does this code print?
    let coins = 24;
    coins = coins + 9;
    coins = coins - 25;
    console.log(coins);
32. 32.⚡ What does this code show?
    let name = "Zoya";
    alert("Hi, " + name + "!"); (a) Hi, name! (b) Zoya (c) Hi, Zoya! (d) name
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 2;
    console.log(x + y); (a) 9 (b) Error (c) 72
34. 34.⚡ What number does this code print?
    let a = 39;
    let b = 11;
    console.log(a - b);
35. 35.⚡ What number does this code print?
    let books = 17;
    books = books + 9;
    books = books - 11;
    console.log(books);
36. 36.⚡ What number does this code print?
    let coins = 9;
    coins = coins + 7;
    coins = coins - 7;
    console.log(coins);
37. 37.⚡ What number does this code print?
    let a = 60;
    let b = 7;
    console.log(a - b);
38. 38.⚡ What number does this code print?
    let books = 17;
    books = books + 5;
    books = books - 22;
    console.log(books);
39. 39.⚡ Which word makes a new variable? (a) put (b) give (c) let (d) make
40. 40.⚡ What number does this code print?
    let a = 10;
    let b = 5;
    console.log(a + b);

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