JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 235 · 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 does this code print? (Look at the quotes!)
   let x = "9";
   let y = 7;
   console.log(x + y); (a) 97 (b) 16 (c) Error
2. 2.⚡ What does this code print? (Look at the quotes!)
   let x = "9";
   let y = 1;
   console.log(x + y); (a) 10 (b) 91 (c) Error
3. 3.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .jpg (c) .html (d) .css
4. 4.⚡ Which JavaScript word writes in the console? (a) if (b) console.log() (c) for (d) let
5. 5.⚡ What number does this code print?
   let a = 37;
   let b = 25;
   console.log(a + b);
6. 6.⚡ What number does this code print?
   let score = 7;
   score = score + 13;
   score = score - 6;
   console.log(score);
7. 7.⚡ What does this code print? (Look at the quotes!)
   let x = "2";
   let y = 2;
   console.log(x + y); (a) Error (b) 22 (c) 4
8. 8.⚡ What does this code show?
   let name = "Kabir";
   console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) Kabir (c) Welcome, Kabir! (d) name
9. 9.⚡ Where does console.log() show its output? (a) in the console (b) in the address bar (c) on the title bar (d) on the printer
10. 10.⚡ What number does this code print?
    let a = 39;
    let b = 30;
    console.log(a - b);
11. 11.⚡ What number does this code print?
    let score = 9;
    score = score + 7;
    score = score - 13;
    console.log(score);
12. 12.⚡ What does this code show?
    let name = "Aman";
    alert("Welcome, " + name + "!"); (a) name (b) Aman (c) Welcome, Aman! (d) Welcome, name!
13. 13.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <style> (c) <js> (d) <script>
14. 14.⚡ What number does this code print?
    let a = 32;
    let b = 5;
    console.log(a - b);
15. 15.⚡ What number does this code print?
    let a = 15;
    let b = 7;
    console.log(a - b);
16. 16.⚡ What number does this code print?
    let a = 2;
    let b = 2;
    console.log(a * b);
17. 17.⚡ What number does this code print?
    let a = 26;
    let b = 16;
    console.log(a + b);
18. 18.⚡ What number does this code print?
    let a = 11;
    let b = 11;
    console.log(a * b);
19. 19.⚡ What number does this code print?
    let books = 19;
    books = books + 6;
    books = books - 22;
    console.log(books);
20. 20.⚡ What number does this code print?
    let books = 11;
    books = books + 15;
    books = books - 4;
    console.log(books);
21. 21.⚡ What does JavaScript add to a web page? (a) the page title (b) the domain name (c) only colours (d) actions and changes
22. 22.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 9;
    console.log(x + y); (a) 99 (b) Error (c) 18
23. 23.⚡ What does this code show?
    let name = "Aman";
    console.log("Well done, " + name + "!"); (a) name (b) Well done, name! (c) Well done, Aman! (d) Aman
24. 24.⚡ What number does this code print?
    let score = 14;
    score = score + 2;
    score = score - 6;
    console.log(score);
25. 25.⚡ What number does this code print?
    let a = 2;
    let b = 5;
    console.log(a * b);
26. 26.⚡ What number does this code print?
    let a = 30;
    let b = 25;
    console.log(a - b);
27. 27.⚡ What does this code show?
    let name = "Zoya";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) Zoya (c) name (d) Welcome, Zoya!
28. 28.⚡ Which JavaScript word repeats code? (a) let (b) alert() (c) for (d) console.log()
29. 29.⚡ What does alert() show? (a) a pop-up box (b) a picture (c) a table (d) a new tab
30. 30.⚡ What does this code show?
    let name = "Arjun";
    alert("Welcome, " + name + "!"); (a) name (b) Welcome, name! (c) Arjun (d) Welcome, Arjun!
31. 31.⚡ What number does this code print?
    let score = 28;
    score = score + 16;
    score = score - 17;
    console.log(score);
32. 32.⚡ What number does this code print?
    let runs = 20;
    runs = runs + 5;
    runs = runs - 12;
    console.log(runs);
33. 33.⚡ 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
34. 34.⚡ What number does this code print?
    let a = 49;
    let b = 1;
    console.log(a + b);
35. 35.⚡ What number does this code print?
    let a = 56;
    let b = 3;
    console.log(a + b);
36. 36.⚡ What does this code show?
    let name = "Zoya";
    console.log("Hi, " + name + "!"); (a) Zoya (b) name (c) Hi, Zoya! (d) Hi, name!
37. 37.⚡ What number does this code print?
    let coins = 19;
    coins = coins + 8;
    coins = coins - 3;
    console.log(coins);
38. 38.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 1;
    console.log(x + y); (a) 3 (b) 21 (c) Error
39. 39.⚡ What number does this code print?
    let coins = 13;
    coins = coins + 9;
    coins = coins - 19;
    console.log(coins);
40. 40.⚡ What does this code show?
    let name = "Kabir";
    alert("Hi, " + name + "!"); (a) name (b) Hi, name! (c) Kabir (d) Hi, Kabir!

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