JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 410 · 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 JavaScript add to a web page? (a) only colours (b) the page title (c) actions and changes (d) the domain name
2. 2.⚡ A JavaScript file usually ends with which extension? (a) .jpg (b) .html (c) .css (d) .js
3. 3.⚡ Where does console.log() show its output? (a) on the printer (b) in the console (c) in the address bar (d) on the title bar
4. 4.⚡ Which JavaScript word writes in the console? (a) alert() (b) let (c) console.log() (d) if
5. 5.⚡ What number does this code print?
   let a = 2;
   let b = 4;
   console.log(a * b);
6. 6.⚡ What number does this code print?
   let a = 53;
   let b = 33;
   console.log(a - b);
7. 7.⚡ What does alert() show? (a) a new tab (b) a pop-up box (c) a picture (d) a table
8. 8.⚡ What does this code print? (Look at the quotes!)
   let x = "3";
   let y = 5;
   console.log(x + y); (a) 8 (b) Error (c) 35
9. 9.⚡ Which JavaScript word repeats code? (a) for (b) alert() (c) let (d) if
10. 10.⚡ Which JavaScript word runs code when true? (a) if (b) for (c) console.log() (d) alert()
11. 11.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 3;
    console.log(x + y); (a) 9 (b) 63 (c) Error
12. 12.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 4;
    console.log(x + y); (a) 9 (b) 54 (c) Error
13. 13.⚡ What number does this code print?
    let books = 6;
    books = books + 18;
    books = books - 12;
    console.log(books);
14. 14.⚡ What number does this code print?
    let a = 6;
    let b = 8;
    console.log(a * b);
15. 15.⚡ Which word makes a new variable? (a) put (b) make (c) let (d) give
16. 16.⚡ What does this code show?
    let name = "Aman";
    alert("Well done, " + name + "!"); (a) Well done, Aman! (b) Aman (c) name (d) Well done, name!
17. 17.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <js> (c) <style> (d) <script>
18. 18.⚡ Which JavaScript word shows a pop-up box? (a) for (b) alert() (c) console.log() (d) let
19. 19.⚡ What number does this code print?
    let score = 11;
    score = score + 5;
    score = score - 7;
    console.log(score);
20. 20.⚡ What number does this code print?
    let score = 6;
    score = score + 15;
    score = score - 4;
    console.log(score);
21. 21.⚡ What number does this code print?
    let score = 18;
    score = score + 15;
    score = score - 10;
    console.log(score);
22. 22.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 4;
    console.log(x + y); (a) 13 (b) Error (c) 94
23. 23.⚡ What number does this code print?
    let a = 30;
    let b = 26;
    console.log(a + b);
24. 24.⚡ What number does this code print?
    let a = 28;
    let b = 37;
    console.log(a + b);
25. 25.⚡ Which JavaScript word makes a new variable? (a) if (b) for (c) console.log() (d) let
26. 26.⚡ What number does this code print?
    let marks = 10;
    marks = marks + 10;
    marks = marks - 8;
    console.log(marks);
27. 27.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 1;
    console.log(x + y); (a) 7 (b) Error (c) 61
28. 28.⚡ What number does this code print?
    let a = 45;
    let b = 24;
    console.log(a - b);
29. 29.⚡ What number does this code print?
    let a = 14;
    let b = 2;
    console.log(a + b);
30. 30.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 7;
    console.log(x + y); (a) 17 (b) 8 (c) Error
31. 31.⚡ What does this code show?
    let name = "Arjun";
    console.log("Well done, " + name + "!"); (a) Well done, Arjun! (b) Arjun (c) Well done, name! (d) name
32. 32.⚡ What does this code show?
    let name = "Riya";
    console.log("Well done, " + name + "!"); (a) Well done, name! (b) Well done, Riya! (c) name (d) Riya
33. 33.⚡ What number does this code print?
    let a = 12;
    let b = 7;
    console.log(a * b);
34. 34.⚡ What number does this code print?
    let a = 48;
    let b = 35;
    console.log(a - b);
35. 35.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 3;
    console.log(x + y); (a) Error (b) 6 (c) 33
36. 36.⚡ What number does this code print?
    let a = 43;
    let b = 25;
    console.log(a + b);
37. 37.⚡ What number does this code print?
    let apples = 12;
    apples = apples + 16;
    apples = apples - 6;
    console.log(apples);
38. 38.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 4;
    console.log(x + y); (a) 44 (b) 8 (c) Error
39. 39.⚡ What number does this code print?
    let a = 53;
    let b = 26;
    console.log(a - b);
40. 40.⚡ What number does this code print?
    let score = 10;
    score = score + 19;
    score = score - 26;
    console.log(score);

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