JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 401 · 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 marks = 25;
   marks = marks + 2;
   marks = marks - 10;
   console.log(marks);
2. 2.⚡ Which word makes a new variable? (a) give (b) put (c) make (d) let
3. 3.⚡ What number does this code print?
   let books = 20;
   books = books + 16;
   books = books - 16;
   console.log(books);
4. 4.⚡ What number does this code print?
   let a = 9;
   let b = 35;
   console.log(a + b);
5. 5.⚡ What does JavaScript add to a web page? (a) the domain name (b) actions and changes (c) the page title (d) only colours
6. 6.⚡ Which JavaScript word shows a pop-up box? (a) for (b) console.log() (c) if (d) alert()
7. 7.⚡ Which JavaScript word writes in the console? (a) let (b) if (c) alert() (d) console.log()
8. 8.⚡ What number does this code print?
   let a = 5;
   let b = 9;
   console.log(a * b);
9. 9.⚡ What number does this code print?
   let a = 8;
   let b = 9;
   console.log(a * b);
10. 10.⚡ What number does this code print?
    let a = 5;
    let b = 10;
    console.log(a * b);
11. 11.⚡ Where does console.log() show its output? (a) in the address bar (b) on the title bar (c) in the console (d) on the printer
12. 12.⚡ Which JavaScript word repeats code? (a) let (b) if (c) console.log() (d) for
13. 13.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .js (c) .css (d) .jpg
14. 14.⚡ What does alert() show? (a) a picture (b) a new tab (c) a table (d) a pop-up box
15. 15.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <js> (c) <style> (d) <script>
16. 16.⚡ What number does this code print?
    let apples = 22;
    apples = apples + 14;
    apples = apples - 5;
    console.log(apples);
17. 17.⚡ Which JavaScript word makes a new variable? (a) alert() (b) console.log() (c) for (d) let
18. 18.⚡ What number does this code print?
    let a = 52;
    let b = 9;
    console.log(a - b);
19. 19.⚡ What number does this code print?
    let books = 9;
    books = books + 2;
    books = books - 6;
    console.log(books);
20. 20.⚡ What number does this code print?
    let coins = 6;
    coins = coins + 3;
    coins = coins - 7;
    console.log(coins);
21. 21.⚡ What number does this code print?
    let a = 48;
    let b = 5;
    console.log(a + b);
22. 22.⚡ 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
23. 23.⚡ What number does this code print?
    let a = 8;
    let b = 4;
    console.log(a * b);
24. 24.⚡ What number does this code print?
    let a = 3;
    let b = 3;
    console.log(a * b);
25. 25.⚡ What does this code show?
    let name = "Riya";
    alert("Well done, " + name + "!"); (a) Well done, name! (b) Well done, Riya! (c) Riya (d) name
26. 26.⚡ What number does this code print?
    let a = 17;
    let b = 11;
    console.log(a + b);
27. 27.⚡ What number does this code print?
    let a = 58;
    let b = 5;
    console.log(a + b);
28. 28.⚡ What number does this code print?
    let a = 17;
    let b = 11;
    console.log(a - b);
29. 29.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 7;
    console.log(x + y); (a) Error (b) 67 (c) 13
30. 30.⚡ What number does this code print?
    let score = 30;
    score = score + 9;
    score = score - 2;
    console.log(score);
31. 31.⚡ What number does this code print?
    let a = 44;
    let b = 15;
    console.log(a + b);
32. 32.⚡ Which JavaScript word runs code when true? (a) console.log() (b) alert() (c) let (d) if
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 9;
    console.log(x + y); (a) Error (b) 15 (c) 69
34. 34.⚡ What number does this code print?
    let a = 20;
    let b = 4;
    console.log(a - b);
35. 35.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 9;
    console.log(x + y); (a) 12 (b) Error (c) 39
36. 36.⚡ What does this code show?
    let name = "Meera";
    alert("Welcome, " + name + "!"); (a) Welcome, name! (b) Meera (c) Welcome, Meera! (d) name
37. 37.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Hello, Kabir! (d) Kabir
38. 38.⚡ What does this code show?
    let name = "Meera";
    alert("Hi, " + name + "!"); (a) Meera (b) Hi, name! (c) name (d) Hi, Meera!
39. 39.⚡ What does this code show?
    let name = "Arjun";
    console.log("Well done, " + name + "!"); (a) Arjun (b) Well done, Arjun! (c) name (d) Well done, name!
40. 40.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 9;
    console.log(x + y); (a) 79 (b) 16 (c) Error

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