JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 721 · 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 = 8;
   let b = 37;
   console.log(a + b);
2. 2.⚡ Which tag holds JavaScript in a page? (a) <script> (b) <code> (c) <style> (d) <js>
3. 3.⚡ A JavaScript file usually ends with which extension? (a) .jpg (b) .css (c) .html (d) .js
4. 4.⚡ Which word makes a new variable? (a) let (b) make (c) give (d) put
5. 5.⚡ What number does this code print?
   let a = 22;
   let b = 7;
   console.log(a + b);
6. 6.⚡ What does JavaScript add to a web page? (a) the domain name (b) the page title (c) actions and changes (d) only colours
7. 7.⚡ What number does this code print?
   let runs = 28;
   runs = runs + 8;
   runs = runs - 28;
   console.log(runs);
8. 8.⚡ What number does this code print?
   let coins = 7;
   coins = coins + 11;
   coins = coins - 5;
   console.log(coins);
9. 9.⚡ What does this code print? (Look at the quotes!)
   let x = "2";
   let y = 3;
   console.log(x + y); (a) 23 (b) 5 (c) Error
10. 10.⚡ What number does this code print?
    let runs = 8;
    runs = runs + 3;
    runs = runs - 2;
    console.log(runs);
11. 11.⚡ What number does this code print?
    let score = 9;
    score = score + 13;
    score = score - 18;
    console.log(score);
12. 12.⚡ What number does this code print?
    let apples = 25;
    apples = apples + 4;
    apples = apples - 28;
    console.log(apples);
13. 13.⚡ What number does this code print?
    let apples = 6;
    apples = apples + 3;
    apples = apples - 1;
    console.log(apples);
14. 14.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 6;
    console.log(x + y); (a) 66 (b) 12 (c) Error
15. 15.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 1;
    console.log(x + y); (a) 6 (b) Error (c) 51
16. 16.⚡ What number does this code print?
    let a = 10;
    let b = 5;
    console.log(a * b);
17. 17.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 2;
    console.log(x + y); (a) Error (b) 4 (c) 22
18. 18.⚡ Which JavaScript word shows a pop-up box? (a) console.log() (b) let (c) for (d) alert()
19. 19.⚡ 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
20. 20.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 8;
    console.log(x + y); (a) 14 (b) Error (c) 68
21. 21.⚡ What number does this code print?
    let a = 55;
    let b = 18;
    console.log(a - b);
22. 22.⚡ What number does this code print?
    let a = 27;
    let b = 18;
    console.log(a - b);
23. 23.⚡ What number does this code print?
    let a = 2;
    let b = 8;
    console.log(a * b);
24. 24.⚡ Which JavaScript word repeats code? (a) let (b) console.log() (c) for (d) alert()
25. 25.⚡ What number does this code print?
    let a = 11;
    let b = 2;
    console.log(a * b);
26. 26.⚡ What number does this code print?
    let score = 9;
    score = score + 8;
    score = score - 10;
    console.log(score);
27. 27.⚡ Which JavaScript word writes in the console? (a) console.log() (b) alert() (c) for (d) let
28. 28.⚡ What number does this code print?
    let runs = 5;
    runs = runs + 4;
    runs = runs - 6;
    console.log(runs);
29. 29.⚡ What number does this code print?
    let a = 9;
    let b = 9;
    console.log(a * b);
30. 30.⚡ What number does this code print?
    let runs = 25;
    runs = runs + 20;
    runs = runs - 33;
    console.log(runs);
31. 31.⚡ Where does console.log() show its output? (a) on the printer (b) in the address bar (c) in the console (d) on the title bar
32. 32.⚡ What number does this code print?
    let a = 19;
    let b = 18;
    console.log(a + b);
33. 33.⚡ What does this code show?
    let name = "Kabir";
    console.log("Welcome, " + name + "!"); (a) name (b) Welcome, Kabir! (c) Welcome, name! (d) Kabir
34. 34.⚡ What number does this code print?
    let a = 51;
    let b = 14;
    console.log(a + b);
35. 35.⚡ What number does this code print?
    let a = 12;
    let b = 3;
    console.log(a * b);
36. 36.⚡ What number does this code print?
    let books = 18;
    books = books + 5;
    books = books - 22;
    console.log(books);
37. 37.⚡ What does alert() show? (a) a picture (b) a table (c) a pop-up box (d) a new tab
38. 38.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 4;
    console.log(x + y); (a) 13 (b) 94 (c) Error
39. 39.⚡ Which JavaScript word runs code when true? (a) console.log() (b) for (c) if (d) let
40. 40.⚡ What number does this code print?
    let a = 12;
    let b = 7;
    console.log(a * b);

Free html and css lessons, practice and worksheets at talentjr.in/html-css-for-kids