JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 70 · 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 = 10;
   let b = 5;
   console.log(a * b);
2. 2.⚡ What does this code print? (Look at the quotes!)
   let x = "2";
   let y = 2;
   console.log(x + y); (a) 22 (b) 4 (c) Error
3. 3.⚡ Which JavaScript word writes in the console? (a) for (b) console.log() (c) let (d) alert()
4. 4.⚡ What number does this code print?
   let a = 18;
   let b = 19;
   console.log(a + b);
5. 5.⚡ What number does this code print?
   let a = 2;
   let b = 4;
   console.log(a * b);
6. 6.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <style> (c) <script> (d) <js>
7. 7.⚡ What does this code print? (Look at the quotes!)
   let x = "2";
   let y = 4;
   console.log(x + y); (a) 24 (b) 6 (c) Error
8. 8.⚡ What number does this code print?
   let a = 3;
   let b = 2;
   console.log(a * b);
9. 9.⚡ What does this code print? (Look at the quotes!)
   let x = "7";
   let y = 4;
   console.log(x + y); (a) Error (b) 74 (c) 11
10. 10.⚡ Which JavaScript word shows a pop-up box? (a) let (b) for (c) console.log() (d) alert()
11. 11.⚡ What number does this code print?
    let coins = 14;
    coins = coins + 17;
    coins = coins - 21;
    console.log(coins);
12. 12.⚡ What number does this code print?
    let books = 15;
    books = books + 3;
    books = books - 14;
    console.log(books);
13. 13.⚡ Which JavaScript word runs code when true? (a) if (b) let (c) console.log() (d) for
14. 14.⚡ What number does this code print?
    let marks = 16;
    marks = marks + 6;
    marks = marks - 1;
    console.log(marks);
15. 15.⚡ What number does this code print?
    let a = 55;
    let b = 7;
    console.log(a + b);
16. 16.⚡ What number does this code print?
    let score = 27;
    score = score + 19;
    score = score - 29;
    console.log(score);
17. 17.⚡ Which JavaScript word repeats code? (a) if (b) let (c) alert() (d) for
18. 18.⚡ Where does console.log() show its output? (a) on the printer (b) in the address bar (c) on the title bar (d) in the console
19. 19.⚡ What does JavaScript add to a web page? (a) the page title (b) the domain name (c) actions and changes (d) only colours
20. 20.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .jpg (c) .js (d) .css
21. 21.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 3;
    console.log(x + y); (a) Error (b) 7 (c) 43
22. 22.⚡ What does this code show?
    let name = "Meera";
    console.log("Hello, " + name + "!"); (a) Hello, Meera! (b) Meera (c) name (d) Hello, name!
23. 23.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 8;
    console.log(x + y); (a) 12 (b) Error (c) 48
24. 24.⚡ What number does this code print?
    let apples = 12;
    apples = apples + 4;
    apples = apples - 3;
    console.log(apples);
25. 25.⚡ What does this code show?
    let name = "Aman";
    console.log("Well done, " + name + "!"); (a) Aman (b) Well done, Aman! (c) Well done, name! (d) name
26. 26.⚡ What does alert() show? (a) a table (b) a picture (c) a new tab (d) a pop-up box
27. 27.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hi, " + name + "!"); (a) Kabir (b) Hi, name! (c) name (d) Hi, Kabir!
28. 28.⚡ What number does this code print?
    let a = 54;
    let b = 26;
    console.log(a + b);
29. 29.⚡ What number does this code print?
    let apples = 29;
    apples = apples + 18;
    apples = apples - 23;
    console.log(apples);
30. 30.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 1;
    console.log(x + y); (a) 8 (b) 71 (c) Error
31. 31.⚡ What number does this code print?
    let marks = 27;
    marks = marks + 2;
    marks = marks - 11;
    console.log(marks);
32. 32.⚡ Which JavaScript word makes a new variable? (a) for (b) if (c) alert() (d) let
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 8;
    console.log(x + y); (a) Error (b) 38 (c) 11
34. 34.⚡ What number does this code print?
    let score = 22;
    score = score + 18;
    score = score - 34;
    console.log(score);
35. 35.⚡ What number does this code print?
    let apples = 27;
    apples = apples + 16;
    apples = apples - 41;
    console.log(apples);
36. 36.⚡ What number does this code print?
    let a = 38;
    let b = 7;
    console.log(a - b);
37. 37.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 2;
    console.log(x + y); (a) 9 (b) 72 (c) Error
38. 38.⚡ What does this code show?
    let name = "Zoya";
    alert("Hi, " + name + "!"); (a) Zoya (b) name (c) Hi, Zoya! (d) Hi, name!
39. 39.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 1;
    console.log(x + y); (a) 7 (b) 61 (c) Error
40. 40.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 4;
    console.log(x + y); (a) 5 (b) 14 (c) Error

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