JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 381 · 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 books = 24;
   books = books + 15;
   books = books - 26;
   console.log(books);
2. 2.⚡ Which word makes a new variable? (a) give (b) let (c) make (d) put
3. 3.⚡ What number does this code print?
   let a = 8;
   let b = 12;
   console.log(a + b);
4. 4.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .html (c) .js (d) .jpg
5. 5.⚡ What does this code print? (Look at the quotes!)
   let x = "5";
   let y = 9;
   console.log(x + y); (a) 14 (b) Error (c) 59
6. 6.⚡ Which JavaScript word repeats code? (a) if (b) for (c) console.log() (d) let
7. 7.⚡ What does alert() show? (a) a new tab (b) a pop-up box (c) a picture (d) a table
8. 8.⚡ Where does console.log() show its output? (a) in the address bar (b) on the title bar (c) on the printer (d) in the console
9. 9.⚡ Which JavaScript word runs code when true? (a) alert() (b) for (c) if (d) let
10. 10.⚡ What number does this code print?
    let a = 40;
    let b = 26;
    console.log(a - b);
11. 11.⚡ What number does this code print?
    let a = 22;
    let b = 16;
    console.log(a - b);
12. 12.⚡ Which JavaScript word shows a pop-up box? (a) let (b) for (c) alert() (d) if
13. 13.⚡ What number does this code print?
    let runs = 14;
    runs = runs + 9;
    runs = runs - 4;
    console.log(runs);
14. 14.⚡ What number does this code print?
    let books = 10;
    books = books + 14;
    books = books - 9;
    console.log(books);
15. 15.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 9;
    console.log(x + y); (a) 69 (b) 15 (c) Error
16. 16.⚡ What number does this code print?
    let apples = 5;
    apples = apples + 19;
    apples = apples - 18;
    console.log(apples);
17. 17.⚡ What does this code show?
    let name = "Zoya";
    alert("Well done, " + name + "!"); (a) name (b) Zoya (c) Well done, name! (d) Well done, Zoya!
18. 18.⚡ What number does this code print?
    let a = 28;
    let b = 8;
    console.log(a - b);
19. 19.⚡ What number does this code print?
    let a = 18;
    let b = 23;
    console.log(a + b);
20. 20.⚡ What number does this code print?
    let apples = 13;
    apples = apples + 13;
    apples = apples - 22;
    console.log(apples);
21. 21.⚡ 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
22. 22.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <script> (c) <js> (d) <style>
23. 23.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 7;
    console.log(x + y); (a) 57 (b) Error (c) 12
24. 24.⚡ What does this code show?
    let name = "Zoya";
    alert("Hi, " + name + "!"); (a) Zoya (b) Hi, Zoya! (c) Hi, name! (d) name
25. 25.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 5;
    console.log(x + y); (a) 55 (b) 10 (c) Error
26. 26.⚡ What number does this code print?
    let a = 58;
    let b = 7;
    console.log(a - b);
27. 27.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 1;
    console.log(x + y); (a) 9 (b) Error (c) 81
28. 28.⚡ What number does this code print?
    let books = 20;
    books = books + 3;
    books = books - 10;
    console.log(books);
29. 29.⚡ What number does this code print?
    let a = 19;
    let b = 10;
    console.log(a + b);
30. 30.⚡ Which JavaScript word writes in the console? (a) console.log() (b) if (c) let (d) for
31. 31.⚡ What does JavaScript add to a web page? (a) the page title (b) the domain name (c) only colours (d) actions and changes
32. 32.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 6;
    console.log(x + y); (a) 26 (b) Error (c) 8
33. 33.⚡ What number does this code print?
    let coins = 27;
    coins = coins + 8;
    coins = coins - 7;
    console.log(coins);
34. 34.⚡ What number does this code print?
    let a = 46;
    let b = 2;
    console.log(a - b);
35. 35.⚡ Which JavaScript word makes a new variable? (a) alert() (b) if (c) console.log() (d) let
36. 36.⚡ What does this code show?
    let name = "Aman";
    alert("Well done, " + name + "!"); (a) Well done, name! (b) Well done, Aman! (c) Aman (d) name
37. 37.⚡ What number does this code print?
    let a = 47;
    let b = 35;
    console.log(a + b);
38. 38.⚡ What number does this code print?
    let a = 5;
    let b = 12;
    console.log(a * b);
39. 39.⚡ What number does this code print?
    let a = 16;
    let b = 3;
    console.log(a + b);
40. 40.⚡ What does this code show?
    let name = "Arjun";
    alert("Hello, " + name + "!"); (a) name (b) Hello, Arjun! (c) Hello, name! (d) Arjun

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