JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 242 · 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 = 3;
   let b = 8;
   console.log(a * b);
2. 2.⚡ Which JavaScript word runs code when true? (a) if (b) let (c) console.log() (d) for
3. 3.⚡ What number does this code print?
   let coins = 18;
   coins = coins + 17;
   coins = coins - 31;
   console.log(coins);
4. 4.⚡ What does this code print? (Look at the quotes!)
   let x = "8";
   let y = 2;
   console.log(x + y); (a) 82 (b) Error (c) 10
5. 5.⚡ What number does this code print?
   let a = 8;
   let b = 2;
   console.log(a * b);
6. 6.⚡ What number does this code print?
   let runs = 9;
   runs = runs + 20;
   runs = runs - 9;
   console.log(runs);
7. 7.⚡ What number does this code print?
   let score = 23;
   score = score + 7;
   score = score - 26;
   console.log(score);
8. 8.⚡ What number does this code print?
   let score = 18;
   score = score + 10;
   score = score - 13;
   console.log(score);
9. 9.⚡ What does this code print? (Look at the quotes!)
   let x = "1";
   let y = 1;
   console.log(x + y); (a) Error (b) 2 (c) 11
10. 10.⚡ What number does this code print?
    let a = 16;
    let b = 25;
    console.log(a + b);
11. 11.⚡ What number does this code print?
    let apples = 24;
    apples = apples + 6;
    apples = apples - 4;
    console.log(apples);
12. 12.⚡ What number does this code print?
    let a = 24;
    let b = 15;
    console.log(a - b);
13. 13.⚡ What number does this code print?
    let a = 53;
    let b = 11;
    console.log(a - b);
14. 14.⚡ What number does this code print?
    let a = 49;
    let b = 12;
    console.log(a - b);
15. 15.⚡ What number does this code print?
    let a = 40;
    let b = 4;
    console.log(a + b);
16. 16.⚡ Which JavaScript word makes a new variable? (a) if (b) for (c) let (d) console.log()
17. 17.⚡ What number does this code print?
    let a = 55;
    let b = 36;
    console.log(a + b);
18. 18.⚡ What number does this code print?
    let a = 39;
    let b = 29;
    console.log(a - b);
19. 19.⚡ What does this code show?
    let name = "Riya";
    alert("Welcome, " + name + "!"); (a) Welcome, name! (b) Riya (c) name (d) Welcome, Riya!
20. 20.⚡ Which tag holds JavaScript in a page? (a) <script> (b) <style> (c) <code> (d) <js>
21. 21.⚡ Where does console.log() show its output? (a) in the address bar (b) on the printer (c) in the console (d) on the title bar
22. 22.⚡ What number does this code print?
    let a = 41;
    let b = 40;
    console.log(a - b);
23. 23.⚡ What does JavaScript add to a web page? (a) the domain name (b) the page title (c) actions and changes (d) only colours
24. 24.⚡ What number does this code print?
    let a = 26;
    let b = 10;
    console.log(a - b);
25. 25.⚡ What does alert() show? (a) a table (b) a picture (c) a new tab (d) a pop-up box
26. 26.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hi, " + name + "!"); (a) name (b) Kabir (c) Hi, name! (d) Hi, Kabir!
27. 27.⚡ What number does this code print?
    let a = 12;
    let b = 6;
    console.log(a + b);
28. 28.⚡ Which JavaScript word repeats code? (a) console.log() (b) alert() (c) for (d) let
29. 29.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 3;
    console.log(x + y); (a) 83 (b) 11 (c) Error
30. 30.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 5;
    console.log(x + y); (a) 65 (b) 11 (c) Error
31. 31.⚡ Which JavaScript word shows a pop-up box? (a) let (b) for (c) if (d) alert()
32. 32.⚡ Which JavaScript word writes in the console? (a) console.log() (b) for (c) alert() (d) if
33. 33.⚡ What number does this code print?
    let books = 26;
    books = books + 3;
    books = books - 1;
    console.log(books);
34. 34.⚡ What number does this code print?
    let a = 44;
    let b = 1;
    console.log(a - b);
35. 35.⚡ What number does this code print?
    let apples = 23;
    apples = apples + 4;
    apples = apples - 11;
    console.log(apples);
36. 36.⚡ What number does this code print?
    let a = 7;
    let b = 6;
    console.log(a * b);
37. 37.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 6;
    console.log(x + y); (a) Error (b) 26 (c) 8
38. 38.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 6;
    console.log(x + y); (a) Error (b) 96 (c) 15
39. 39.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .jpg (c) .css (d) .js
40. 40.⚡ What number does this code print?
    let a = 57;
    let b = 4;
    console.log(a - b);

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