JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 13 · 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 a = 34;
   let b = 2;
   console.log(a + b);
2. 2.⚡ What does this code print? (Look at the quotes!)
   let x = "9";
   let y = 6;
   console.log(x + y); (a) 15 (b) 96 (c) Error
3. 3.⚡ What does this code print? (Look at the quotes!)
   let x = "3";
   let y = 4;
   console.log(x + y); (a) 34 (b) 7 (c) Error
4. 4.⚡ What does this code print? (Look at the quotes!)
   let x = "5";
   let y = 1;
   console.log(x + y); (a) Error (b) 51 (c) 6
5. 5.⚡ What does this code print? (Look at the quotes!)
   let x = "8";
   let y = 3;
   console.log(x + y); (a) Error (b) 11 (c) 83
6. 6.⚡ What number does this code print?
   let a = 42;
   let b = 17;
   console.log(a - b);
7. 7.⚡ 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
8. 8.⚡ What does this code print? (Look at the quotes!)
   let x = "1";
   let y = 7;
   console.log(x + y); (a) Error (b) 8 (c) 17
9. 9.⚡ What does alert() show? (a) a table (b) a picture (c) a pop-up box (d) a new tab
10. 10.⚡ What number does this code print?
    let a = 4;
    let b = 8;
    console.log(a * b);
11. 11.⚡ Which JavaScript word shows a pop-up box? (a) console.log() (b) if (c) alert() (d) let
12. 12.⚡ Which JavaScript word repeats code? (a) console.log() (b) for (c) alert() (d) if
13. 13.⚡ What number does this code print?
    let a = 7;
    let b = 7;
    console.log(a * b);
14. 14.⚡ Which JavaScript word writes in the console? (a) for (b) alert() (c) console.log() (d) let
15. 15.⚡ What number does this code print?
    let a = 51;
    let b = 1;
    console.log(a - b);
16. 16.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .jpg (c) .js (d) .css
17. 17.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 4;
    console.log(x + y); (a) 8 (b) 44 (c) Error
18. 18.⚡ What does this code show?
    let name = "Kabir";
    console.log("Well done, " + name + "!"); (a) Well done, name! (b) Kabir (c) name (d) Well done, Kabir!
19. 19.⚡ What number does this code print?
    let apples = 18;
    apples = apples + 4;
    apples = apples - 22;
    console.log(apples);
20. 20.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 5;
    console.log(x + y); (a) Error (b) 65 (c) 11
21. 21.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 3;
    console.log(x + y); (a) 63 (b) Error (c) 9
22. 22.⚡ What number does this code print?
    let a = 7;
    let b = 28;
    console.log(a + b);
23. 23.⚡ What does this code show?
    let name = "Aman";
    console.log("Well done, " + name + "!"); (a) Well done, name! (b) Aman (c) name (d) Well done, Aman!
24. 24.⚡ What number does this code print?
    let a = 10;
    let b = 5;
    console.log(a * b);
25. 25.⚡ What number does this code print?
    let a = 11;
    let b = 10;
    console.log(a * b);
26. 26.⚡ What number does this code print?
    let books = 30;
    books = books + 12;
    books = books - 38;
    console.log(books);
27. 27.⚡ What does JavaScript add to a web page? (a) the page title (b) the domain name (c) only colours (d) actions and changes
28. 28.⚡ What number does this code print?
    let a = 58;
    let b = 4;
    console.log(a - b);
29. 29.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <js> (c) <style> (d) <script>
30. 30.⚡ Which JavaScript word makes a new variable? (a) for (b) alert() (c) let (d) console.log()
31. 31.⚡ What number does this code print?
    let a = 16;
    let b = 11;
    console.log(a - b);
32. 32.⚡ What number does this code print?
    let a = 53;
    let b = 38;
    console.log(a - b);
33. 33.⚡ What number does this code print?
    let a = 10;
    let b = 4;
    console.log(a * b);
34. 34.⚡ What number does this code print?
    let books = 11;
    books = books + 11;
    books = books - 12;
    console.log(books);
35. 35.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 3;
    console.log(x + y); (a) Error (b) 13 (c) 4
36. 36.⚡ What number does this code print?
    let a = 47;
    let b = 16;
    console.log(a - b);
37. 37.⚡ What number does this code print?
    let marks = 5;
    marks = marks + 15;
    marks = marks - 5;
    console.log(marks);
38. 38.⚡ What number does this code print?
    let a = 42;
    let b = 27;
    console.log(a - b);
39. 39.⚡ What number does this code print?
    let a = 31;
    let b = 23;
    console.log(a + b);
40. 40.⚡ What does this code show?
    let name = "Zoya";
    alert("Well done, " + name + "!"); (a) name (b) Well done, Zoya! (c) Zoya (d) Well done, name!

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