JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 770 · 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 number does this code print?
   let a = 9;
   let b = 12;
   console.log(a * b);
2. 2.⚡ What number does this code print?
   let a = 10;
   let b = 2;
   console.log(a * b);
3. 3.⚡ What does this code print? (Look at the quotes!)
   let x = "3";
   let y = 1;
   console.log(x + y); (a) Error (b) 4 (c) 31
4. 4.⚡ What number does this code print?
   let apples = 14;
   apples = apples + 4;
   apples = apples - 17;
   console.log(apples);
5. 5.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <script> (c) <js> (d) <style>
6. 6.⚡ What does this code print? (Look at the quotes!)
   let x = "8";
   let y = 3;
   console.log(x + y); (a) Error (b) 83 (c) 11
7. 7.⚡ What does this code print? (Look at the quotes!)
   let x = "2";
   let y = 7;
   console.log(x + y); (a) 27 (b) 9 (c) Error
8. 8.⚡ Which JavaScript word shows a pop-up box? (a) console.log() (b) let (c) for (d) alert()
9. 9.⚡ What does JavaScript add to a web page? (a) the domain name (b) only colours (c) the page title (d) actions and changes
10. 10.⚡ Which JavaScript word writes in the console? (a) if (b) alert() (c) let (d) console.log()
11. 11.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 8;
    console.log(x + y); (a) Error (b) 68 (c) 14
12. 12.⚡ What number does this code print?
    let a = 22;
    let b = 15;
    console.log(a - b);
13. 13.⚡ What does this code show?
    let name = "Riya";
    alert("Hi, " + name + "!"); (a) Hi, name! (b) name (c) Riya (d) Hi, Riya!
14. 14.⚡ What number does this code print?
    let coins = 23;
    coins = coins + 16;
    coins = coins - 2;
    console.log(coins);
15. 15.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 2;
    console.log(x + y); (a) 7 (b) 52 (c) Error
16. 16.⚡ What number does this code print?
    let a = 59;
    let b = 31;
    console.log(a - b);
17. 17.⚡ What number does this code print?
    let runs = 6;
    runs = runs + 7;
    runs = runs - 5;
    console.log(runs);
18. 18.⚡ What number does this code print?
    let a = 4;
    let b = 9;
    console.log(a * b);
19. 19.⚡ Which word makes a new variable? (a) let (b) make (c) put (d) give
20. 20.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .html (c) .jpg (d) .js
21. 21.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 9;
    console.log(x + y); (a) 11 (b) Error (c) 29
22. 22.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 3;
    console.log(x + y); (a) Error (b) 9 (c) 63
23. 23.⚡ What number does this code print?
    let score = 23;
    score = score + 6;
    score = score - 20;
    console.log(score);
24. 24.⚡ Which JavaScript word repeats code? (a) if (b) for (c) console.log() (d) let
25. 25.⚡ What number does this code print?
    let a = 54;
    let b = 24;
    console.log(a - b);
26. 26.⚡ Which JavaScript word runs code when true? (a) if (b) for (c) alert() (d) console.log()
27. 27.⚡ Which JavaScript word makes a new variable? (a) if (b) console.log() (c) alert() (d) let
28. 28.⚡ What number does this code print?
    let books = 29;
    books = books + 11;
    books = books - 16;
    console.log(books);
29. 29.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 5;
    console.log(x + y); (a) 95 (b) Error (c) 14
30. 30.⚡ What number does this code print?
    let a = 9;
    let b = 6;
    console.log(a * b);
31. 31.⚡ What number does this code print?
    let a = 4;
    let b = 11;
    console.log(a * b);
32. 32.⚡ What does alert() show? (a) a picture (b) a pop-up box (c) a new tab (d) a table
33. 33.⚡ What does this code show?
    let name = "Arjun";
    console.log("Hello, " + name + "!"); (a) Arjun (b) name (c) Hello, name! (d) Hello, Arjun!
34. 34.⚡ What does this code show?
    let name = "Aman";
    console.log("Hello, " + name + "!"); (a) Aman (b) Hello, Aman! (c) Hello, name! (d) name
35. 35.⚡ What does this code show?
    let name = "Aman";
    console.log("Well done, " + name + "!"); (a) name (b) Well done, Aman! (c) Well done, name! (d) Aman
36. 36.⚡ What does this code show?
    let name = "Zoya";
    alert("Welcome, " + name + "!"); (a) name (b) Welcome, name! (c) Welcome, Zoya! (d) Zoya
37. 37.⚡ What number does this code print?
    let a = 55;
    let b = 32;
    console.log(a - b);
38. 38.⚡ What number does this code print?
    let coins = 14;
    coins = coins + 12;
    coins = coins - 20;
    console.log(coins);
39. 39.⚡ Where does console.log() show its output? (a) on the printer (b) in the console (c) in the address bar (d) on the title bar
40. 40.⚡ What does this code show?
    let name = "Aman";
    console.log("Hi, " + name + "!"); (a) Aman (b) name (c) Hi, name! (d) Hi, Aman!

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