JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 769 · 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 show?
   let name = "Riya";
   console.log("Welcome, " + name + "!"); (a) Welcome, Riya! (b) Welcome, name! (c) name (d) Riya
2. 2.⚡ Which JavaScript word shows a pop-up box? (a) if (b) let (c) alert() (d) for
3. 3.⚡ What number does this code print?
   let a = 7;
   let b = 3;
   console.log(a * b);
4. 4.⚡ What number does this code print?
   let books = 20;
   books = books + 3;
   books = books - 5;
   console.log(books);
5. 5.⚡ Which word makes a new variable? (a) make (b) put (c) let (d) give
6. 6.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .js (c) .jpg (d) .html
7. 7.⚡ What does this code print? (Look at the quotes!)
   let x = "1";
   let y = 2;
   console.log(x + y); (a) 3 (b) Error (c) 12
8. 8.⚡ What number does this code print?
   let score = 21;
   score = score + 6;
   score = score - 1;
   console.log(score);
9. 9.⚡ What does JavaScript add to a web page? (a) only colours (b) actions and changes (c) the domain name (d) the page title
10. 10.⚡ Which JavaScript word runs code when true? (a) let (b) alert() (c) if (d) console.log()
11. 11.⚡ What number does this code print?
    let a = 6;
    let b = 5;
    console.log(a - b);
12. 12.⚡ Which JavaScript word writes in the console? (a) console.log() (b) for (c) let (d) alert()
13. 13.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 4;
    console.log(x + y); (a) 74 (b) 11 (c) Error
14. 14.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 2;
    console.log(x + y); (a) 32 (b) 5 (c) Error
15. 15.⚡ What number does this code print?
    let score = 16;
    score = score + 4;
    score = score - 8;
    console.log(score);
16. 16.⚡ Which JavaScript word makes a new variable? (a) let (b) console.log() (c) if (d) for
17. 17.⚡ What does this code show?
    let name = "Aman";
    console.log("Hello, " + name + "!"); (a) name (b) Aman (c) Hello, name! (d) Hello, Aman!
18. 18.⚡ Which JavaScript word repeats code? (a) alert() (b) if (c) for (d) console.log()
19. 19.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 4;
    console.log(x + y); (a) 54 (b) Error (c) 9
20. 20.⚡ Where does console.log() show its output? (a) in the address bar (b) in the console (c) on the title bar (d) on the printer
21. 21.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 9;
    console.log(x + y); (a) 15 (b) Error (c) 69
22. 22.⚡ What does this code show?
    let name = "Meera";
    console.log("Hello, " + name + "!"); (a) Meera (b) Hello, name! (c) name (d) Hello, Meera!
23. 23.⚡ What does this code show?
    let name = "Riya";
    alert("Hi, " + name + "!"); (a) name (b) Riya (c) Hi, name! (d) Hi, Riya!
24. 24.⚡ What does alert() show? (a) a picture (b) a pop-up box (c) a table (d) a new tab
25. 25.⚡ What number does this code print?
    let a = 12;
    let b = 5;
    console.log(a - b);
26. 26.⚡ What does this code show?
    let name = "Aman";
    console.log("Well done, " + name + "!"); (a) Well done, name! (b) name (c) Aman (d) Well done, Aman!
27. 27.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 3;
    console.log(x + y); (a) 12 (b) 93 (c) Error
28. 28.⚡ What number does this code print?
    let apples = 8;
    apples = apples + 13;
    apples = apples - 8;
    console.log(apples);
29. 29.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 5;
    console.log(x + y); (a) Error (b) 15 (c) 6
30. 30.⚡ What number does this code print?
    let a = 54;
    let b = 20;
    console.log(a + b);
31. 31.⚡ 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
32. 32.⚡ What number does this code print?
    let marks = 5;
    marks = marks + 15;
    marks = marks - 19;
    console.log(marks);
33. 33.⚡ What number does this code print?
    let a = 5;
    let b = 9;
    console.log(a * b);
34. 34.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 2;
    console.log(x + y); (a) 8 (b) Error (c) 62
35. 35.⚡ What number does this code print?
    let a = 9;
    let b = 30;
    console.log(a + b);
36. 36.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 1;
    console.log(x + y); (a) 81 (b) Error (c) 9
37. 37.⚡ What does this code show?
    let name = "Arjun";
    alert("Welcome, " + name + "!"); (a) Welcome, Arjun! (b) Welcome, name! (c) Arjun (d) name
38. 38.⚡ What number does this code print?
    let apples = 20;
    apples = apples + 10;
    apples = apples - 10;
    console.log(apples);
39. 39.⚡ 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
40. 40.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 6;
    console.log(x + y); (a) Error (b) 7 (c) 16

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