JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 220 · 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 = "8";
   let y = 2;
   console.log(x + y); (a) Error (b) 10 (c) 82
2. 2.⚡ What number does this code print?
   let a = 31;
   let b = 10;
   console.log(a + b);
3. 3.⚡ What number does this code print?
   let coins = 18;
   coins = coins + 8;
   coins = coins - 25;
   console.log(coins);
4. 4.⚡ What does this code print? (Look at the quotes!)
   let x = "3";
   let y = 7;
   console.log(x + y); (a) 10 (b) 37 (c) Error
5. 5.⚡ What number does this code print?
   let a = 12;
   let b = 2;
   console.log(a * b);
6. 6.⚡ Which JavaScript word repeats code? (a) for (b) let (c) console.log() (d) alert()
7. 7.⚡ Which word makes a new variable? (a) put (b) give (c) let (d) make
8. 8.⚡ Which JavaScript word writes in the console? (a) if (b) alert() (c) console.log() (d) let
9. 9.⚡ Which JavaScript word shows a pop-up box? (a) if (b) alert() (c) let (d) console.log()
10. 10.⚡ What does this code show?
    let name = "Meera";
    alert("Well done, " + name + "!"); (a) Meera (b) Well done, Meera! (c) name (d) Well done, name!
11. 11.⚡ What number does this code print?
    let apples = 19;
    apples = apples + 14;
    apples = apples - 4;
    console.log(apples);
12. 12.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 8;
    console.log(x + y); (a) Error (b) 16 (c) 88
13. 13.⚡ What number does this code print?
    let books = 9;
    books = books + 19;
    books = books - 2;
    console.log(books);
14. 14.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .css (c) .js (d) .jpg
15. 15.⚡ What does alert() show? (a) a pop-up box (b) a new tab (c) a picture (d) a table
16. 16.⚡ What number does this code print?
    let a = 8;
    let b = 8;
    console.log(a * b);
17. 17.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 3;
    console.log(x + y); (a) 7 (b) 43 (c) Error
18. 18.⚡ What number does this code print?
    let a = 5;
    let b = 4;
    console.log(a * b);
19. 19.⚡ What number does this code print?
    let a = 19;
    let b = 9;
    console.log(a - b);
20. 20.⚡ What does this code show?
    let name = "Riya";
    alert("Hello, " + name + "!"); (a) name (b) Hello, name! (c) Riya (d) Hello, Riya!
21. 21.⚡ What does this code show?
    let name = "Riya";
    console.log("Hi, " + name + "!"); (a) Riya (b) name (c) Hi, Riya! (d) Hi, name!
22. 22.⚡ What does this code show?
    let name = "Arjun";
    alert("Well done, " + name + "!"); (a) Well done, name! (b) Well done, Arjun! (c) Arjun (d) name
23. 23.⚡ What number does this code print?
    let coins = 14;
    coins = coins + 4;
    coins = coins - 3;
    console.log(coins);
24. 24.⚡ What number does this code print?
    let a = 17;
    let b = 17;
    console.log(a - b);
25. 25.⚡ What number does this code print?
    let a = 43;
    let b = 9;
    console.log(a - b);
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 1;
    console.log(x + y); (a) 9 (b) Error (c) 81
27. 27.⚡ What number does this code print?
    let a = 4;
    let b = 2;
    console.log(a * b);
28. 28.⚡ What number does this code print?
    let books = 17;
    books = books + 9;
    books = books - 19;
    console.log(books);
29. 29.⚡ What does this code show?
    let name = "Meera";
    alert("Hi, " + name + "!"); (a) Meera (b) Hi, name! (c) Hi, Meera! (d) name
30. 30.⚡ What does JavaScript add to a web page? (a) the domain name (b) only colours (c) actions and changes (d) the page title
31. 31.⚡ What number does this code print?
    let a = 30;
    let b = 19;
    console.log(a - b);
32. 32.⚡ Which JavaScript word runs code when true? (a) let (b) alert() (c) for (d) if
33. 33.⚡ What number does this code print?
    let a = 11;
    let b = 12;
    console.log(a * b);
34. 34.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 8;
    console.log(x + y); (a) 14 (b) 68 (c) Error
35. 35.⚡ What number does this code print?
    let a = 6;
    let b = 30;
    console.log(a + b);
36. 36.⚡ 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
37. 37.⚡ 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
38. 38.⚡ What does this code show?
    let name = "Zoya";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Zoya (d) Hello, Zoya!
39. 39.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 9;
    console.log(x + y); (a) 14 (b) 59 (c) Error
40. 40.⚡ What number does this code print?
    let a = 5;
    let b = 11;
    console.log(a * b);

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