JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 715 · 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 apples = 21;
   apples = apples + 19;
   apples = apples - 4;
   console.log(apples);
2. 2.⚡ What number does this code print?
   let coins = 29;
   coins = coins + 12;
   coins = coins - 22;
   console.log(coins);
3. 3.⚡ What number does this code print?
   let a = 29;
   let b = 23;
   console.log(a - b);
4. 4.⚡ What does alert() show? (a) a table (b) a picture (c) a pop-up box (d) a new tab
5. 5.⚡ What number does this code print?
   let books = 8;
   books = books + 9;
   books = books - 3;
   console.log(books);
6. 6.⚡ What does this code print? (Look at the quotes!)
   let x = "3";
   let y = 5;
   console.log(x + y); (a) 8 (b) 35 (c) Error
7. 7.⚡ What number does this code print?
   let a = 32;
   let b = 8;
   console.log(a - b);
8. 8.⚡ What number does this code print?
   let a = 45;
   let b = 39;
   console.log(a - b);
9. 9.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .html (c) .css (d) .jpg
10. 10.⚡ Where does console.log() show its output? (a) on the printer (b) on the title bar (c) in the address bar (d) in the console
11. 11.⚡ What number does this code print?
    let a = 7;
    let b = 10;
    console.log(a * b);
12. 12.⚡ What does this code show?
    let name = "Kabir";
    console.log("Well done, " + name + "!"); (a) Well done, Kabir! (b) Well done, name! (c) Kabir (d) name
13. 13.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 3;
    console.log(x + y); (a) 13 (b) 4 (c) Error
14. 14.⚡ Which tag holds JavaScript in a page? (a) <js> (b) <code> (c) <script> (d) <style>
15. 15.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 2;
    console.log(x + y); (a) 52 (b) Error (c) 7
16. 16.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 7;
    console.log(x + y); (a) 77 (b) 14 (c) Error
17. 17.⚡ Which JavaScript word writes in the console? (a) console.log() (b) alert() (c) let (d) if
18. 18.⚡ What does this code show?
    let name = "Riya";
    console.log("Well done, " + name + "!"); (a) Well done, Riya! (b) Riya (c) name (d) Well done, name!
19. 19.⚡ What number does this code print?
    let apples = 10;
    apples = apples + 8;
    apples = apples - 15;
    console.log(apples);
20. 20.⚡ What does this code show?
    let name = "Aman";
    alert("Hello, " + name + "!"); (a) Hello, Aman! (b) name (c) Hello, name! (d) Aman
21. 21.⚡ What does this code show?
    let name = "Kabir";
    alert("Hello, " + name + "!"); (a) Kabir (b) Hello, Kabir! (c) name (d) Hello, name!
22. 22.⚡ What number does this code print?
    let a = 3;
    let b = 3;
    console.log(a * b);
23. 23.⚡ What number does this code print?
    let a = 35;
    let b = 12;
    console.log(a + b);
24. 24.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 6;
    console.log(x + y); (a) Error (b) 8 (c) 26
25. 25.⚡ What number does this code print?
    let score = 9;
    score = score + 5;
    score = score - 9;
    console.log(score);
26. 26.⚡ What number does this code print?
    let a = 38;
    let b = 19;
    console.log(a + b);
27. 27.⚡ Which JavaScript word runs code when true? (a) console.log() (b) let (c) alert() (d) if
28. 28.⚡ Which word makes a new variable? (a) let (b) put (c) make (d) give
29. 29.⚡ Which JavaScript word makes a new variable? (a) if (b) console.log() (c) let (d) for
30. 30.⚡ What does JavaScript add to a web page? (a) only colours (b) the page title (c) actions and changes (d) the domain name
31. 31.⚡ What number does this code print?
    let a = 7;
    let b = 6;
    console.log(a * b);
32. 32.⚡ Which JavaScript word repeats code? (a) for (b) let (c) if (d) console.log()
33. 33.⚡ What number does this code print?
    let a = 33;
    let b = 30;
    console.log(a - b);
34. 34.⚡ What number does this code print?
    let a = 23;
    let b = 36;
    console.log(a + b);
35. 35.⚡ What number does this code print?
    let marks = 24;
    marks = marks + 15;
    marks = marks - 9;
    console.log(marks);
36. 36.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) if (c) for (d) let
37. 37.⚡ What number does this code print?
    let a = 8;
    let b = 5;
    console.log(a + b);
38. 38.⚡ What number does this code print?
    let a = 9;
    let b = 4;
    console.log(a * b);
39. 39.⚡ What number does this code print?
    let marks = 29;
    marks = marks + 18;
    marks = marks - 6;
    console.log(marks);
40. 40.⚡ What number does this code print?
    let a = 25;
    let b = 21;
    console.log(a + b);

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