JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 331 · 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 = 34;
   let b = 3;
   console.log(a + b);
2. 2.⚡ What number does this code print?
   let a = 7;
   let b = 5;
   console.log(a - b);
3. 3.⚡ Which JavaScript word shows a pop-up box? (a) console.log() (b) alert() (c) let (d) if
4. 4.⚡ What does JavaScript add to a web page? (a) only colours (b) the domain name (c) the page title (d) actions and changes
5. 5.⚡ Which JavaScript word writes in the console? (a) if (b) let (c) alert() (d) console.log()
6. 6.⚡ What number does this code print?
   let a = 21;
   let b = 23;
   console.log(a + b);
7. 7.⚡ What does this code print? (Look at the quotes!)
   let x = "8";
   let y = 2;
   console.log(x + y); (a) 10 (b) 82 (c) Error
8. 8.⚡ Which JavaScript word repeats code? (a) console.log() (b) for (c) let (d) alert()
9. 9.⚡ What does alert() show? (a) a new tab (b) a pop-up box (c) a table (d) a picture
10. 10.⚡ What number does this code print?
    let score = 23;
    score = score + 4;
    score = score - 8;
    console.log(score);
11. 11.⚡ Where does console.log() show its output? (a) on the title bar (b) on the printer (c) in the address bar (d) in the console
12. 12.⚡ Which JavaScript word runs code when true? (a) if (b) for (c) let (d) console.log()
13. 13.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 9;
    console.log(x + y); (a) Error (b) 79 (c) 16
14. 14.⚡ What number does this code print?
    let apples = 6;
    apples = apples + 7;
    apples = apples - 1;
    console.log(apples);
15. 15.⚡ What number does this code print?
    let a = 2;
    let b = 4;
    console.log(a * b);
16. 16.⚡ What number does this code print?
    let books = 8;
    books = books + 3;
    books = books - 6;
    console.log(books);
17. 17.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 2;
    console.log(x + y); (a) Error (b) 11 (c) 92
18. 18.⚡ Which tag holds JavaScript in a page? (a) <script> (b) <code> (c) <js> (d) <style>
19. 19.⚡ What number does this code print?
    let a = 47;
    let b = 32;
    console.log(a + b);
20. 20.⚡ What number does this code print?
    let a = 21;
    let b = 20;
    console.log(a - b);
21. 21.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 6;
    console.log(x + y); (a) 96 (b) 15 (c) Error
22. 22.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 1;
    console.log(x + y); (a) 3 (b) Error (c) 21
23. 23.⚡ What number does this code print?
    let coins = 24;
    coins = coins + 4;
    coins = coins - 28;
    console.log(coins);
24. 24.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .js (c) .jpg (d) .html
25. 25.⚡ What does this code show?
    let name = "Arjun";
    console.log("Well done, " + name + "!"); (a) name (b) Arjun (c) Well done, Arjun! (d) Well done, name!
26. 26.⚡ What does this code show?
    let name = "Zoya";
    console.log("Well done, " + name + "!"); (a) Well done, name! (b) Well done, Zoya! (c) name (d) Zoya
27. 27.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 5;
    console.log(x + y); (a) Error (b) 65 (c) 11
28. 28.⚡ What number does this code print?
    let apples = 21;
    apples = apples + 19;
    apples = apples - 8;
    console.log(apples);
29. 29.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 9;
    console.log(x + y); (a) Error (b) 99 (c) 18
30. 30.⚡ What number does this code print?
    let apples = 17;
    apples = apples + 15;
    apples = apples - 3;
    console.log(apples);
31. 31.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 6;
    console.log(x + y); (a) Error (b) 56 (c) 11
32. 32.⚡ What number does this code print?
    let a = 44;
    let b = 12;
    console.log(a - b);
33. 33.⚡ What number does this code print?
    let a = 54;
    let b = 26;
    console.log(a + b);
34. 34.⚡ What number does this code print?
    let a = 43;
    let b = 31;
    console.log(a + b);
35. 35.⚡ What does this code show?
    let name = "Meera";
    console.log("Hello, " + name + "!"); (a) Hello, Meera! (b) Meera (c) name (d) Hello, name!
36. 36.⚡ What does this code show?
    let name = "Zoya";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Hello, Zoya! (d) Zoya
37. 37.⚡ Which word makes a new variable? (a) make (b) let (c) put (d) give
38. 38.⚡ What number does this code print?
    let apples = 19;
    apples = apples + 16;
    apples = apples - 23;
    console.log(apples);
39. 39.⚡ What number does this code print?
    let a = 54;
    let b = 14;
    console.log(a + b);
40. 40.⚡ What number does this code print?
    let a = 35;
    let b = 19;
    console.log(a - b);

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