JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 519 · 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 = "Arjun";
   alert("Hello, " + name + "!"); (a) Hello, name! (b) Hello, Arjun! (c) name (d) Arjun
2. 2.⚡ What number does this code print?
   let apples = 5;
   apples = apples + 20;
   apples = apples - 3;
   console.log(apples);
3. 3.⚡ Which JavaScript word runs code when true? (a) let (b) if (c) alert() (d) for
4. 4.⚡ What does JavaScript add to a web page? (a) only colours (b) actions and changes (c) the domain name (d) the page title
5. 5.⚡ What number does this code print?
   let a = 19;
   let b = 29;
   console.log(a + b);
6. 6.⚡ Where does console.log() show its output? (a) on the title bar (b) on the printer (c) in the console (d) in the address bar
7. 7.⚡ Which JavaScript word repeats code? (a) for (b) if (c) alert() (d) let
8. 8.⚡ What number does this code print?
   let a = 16;
   let b = 12;
   console.log(a - b);
9. 9.⚡ Which word makes a new variable? (a) put (b) make (c) give (d) let
10. 10.⚡ What number does this code print?
    let a = 6;
    let b = 4;
    console.log(a * b);
11. 11.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <js> (c) <style> (d) <script>
12. 12.⚡ Which JavaScript word makes a new variable? (a) for (b) if (c) alert() (d) let
13. 13.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 2;
    console.log(x + y); (a) 12 (b) 3 (c) Error
14. 14.⚡ What number does this code print?
    let a = 11;
    let b = 5;
    console.log(a - b);
15. 15.⚡ What does alert() show? (a) a picture (b) a table (c) a pop-up box (d) a new tab
16. 16.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 4;
    console.log(x + y); (a) 12 (b) Error (c) 84
17. 17.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 1;
    console.log(x + y); (a) Error (b) 31 (c) 4
18. 18.⚡ A JavaScript file usually ends with which extension? (a) .jpg (b) .css (c) .html (d) .js
19. 19.⚡ What number does this code print?
    let a = 12;
    let b = 5;
    console.log(a * b);
20. 20.⚡ What does this code show?
    let name = "Arjun";
    alert("Welcome, " + name + "!"); (a) name (b) Welcome, name! (c) Arjun (d) Welcome, Arjun!
21. 21.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 5;
    console.log(x + y); (a) Error (b) 55 (c) 10
22. 22.⚡ What number does this code print?
    let a = 12;
    let b = 7;
    console.log(a * b);
23. 23.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 3;
    console.log(x + y); (a) Error (b) 43 (c) 7
24. 24.⚡ What number does this code print?
    let score = 14;
    score = score + 5;
    score = score - 18;
    console.log(score);
25. 25.⚡ What number does this code print?
    let a = 56;
    let b = 12;
    console.log(a - b);
26. 26.⚡ What number does this code print?
    let score = 7;
    score = score + 15;
    score = score - 13;
    console.log(score);
27. 27.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 1;
    console.log(x + y); (a) Error (b) 8 (c) 71
28. 28.⚡ What number does this code print?
    let books = 20;
    books = books + 16;
    books = books - 4;
    console.log(books);
29. 29.⚡ What number does this code print?
    let coins = 20;
    coins = coins + 10;
    coins = coins - 10;
    console.log(coins);
30. 30.⚡ What number does this code print?
    let a = 12;
    let b = 9;
    console.log(a + b);
31. 31.⚡ Which JavaScript word shows a pop-up box? (a) if (b) for (c) alert() (d) console.log()
32. 32.⚡ What number does this code print?
    let apples = 25;
    apples = apples + 11;
    apples = apples - 14;
    console.log(apples);
33. 33.⚡ What number does this code print?
    let books = 11;
    books = books + 11;
    books = books - 15;
    console.log(books);
34. 34.⚡ What number does this code print?
    let apples = 14;
    apples = apples + 16;
    apples = apples - 5;
    console.log(apples);
35. 35.⚡ What does this code show?
    let name = "Meera";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) name (c) Welcome, Meera! (d) Meera
36. 36.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 9;
    console.log(x + y); (a) Error (b) 89 (c) 17
37. 37.⚡ What does this code show?
    let name = "Riya";
    alert("Hi, " + name + "!"); (a) Hi, name! (b) name (c) Hi, Riya! (d) Riya
38. 38.⚡ What number does this code print?
    let a = 60;
    let b = 12;
    console.log(a + b);
39. 39.⚡ What number does this code print?
    let apples = 14;
    apples = apples + 6;
    apples = apples - 15;
    console.log(apples);
40. 40.⚡ What number does this code print?
    let coins = 7;
    coins = coins + 7;
    coins = coins - 7;
    console.log(coins);

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