JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 728 · 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 alert() show? (a) a new tab (b) a pop-up box (c) a table (d) a picture
2. 2.⚡ What number does this code print?
   let a = 30;
   let b = 6;
   console.log(a + b);
3. 3.⚡ What number does this code print?
   let coins = 6;
   coins = coins + 19;
   coins = coins - 7;
   console.log(coins);
4. 4.⚡ What number does this code print?
   let coins = 24;
   coins = coins + 17;
   coins = coins - 15;
   console.log(coins);
5. 5.⚡ What does this code show?
   let name = "Riya";
   alert("Hi, " + name + "!"); (a) Hi, name! (b) Riya (c) name (d) Hi, Riya!
6. 6.⚡ What does this code print? (Look at the quotes!)
   let x = "5";
   let y = 5;
   console.log(x + y); (a) Error (b) 10 (c) 55
7. 7.⚡ What number does this code print?
   let books = 17;
   books = books + 4;
   books = books - 13;
   console.log(books);
8. 8.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) if (c) let (d) console.log()
9. 9.⚡ What number does this code print?
   let a = 39;
   let b = 27;
   console.log(a - b);
10. 10.⚡ Which word makes a new variable? (a) make (b) put (c) give (d) let
11. 11.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .css (c) .html (d) .jpg
12. 12.⚡ What number does this code print?
    let apples = 10;
    apples = apples + 12;
    apples = apples - 19;
    console.log(apples);
13. 13.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 8;
    console.log(x + y); (a) Error (b) 10 (c) 28
14. 14.⚡ Which JavaScript word makes a new variable? (a) let (b) if (c) console.log() (d) for
15. 15.⚡ What number does this code print?
    let a = 47;
    let b = 5;
    console.log(a + b);
16. 16.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 1;
    console.log(x + y); (a) 7 (b) Error (c) 61
17. 17.⚡ 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
18. 18.⚡ What number does this code print?
    let a = 7;
    let b = 8;
    console.log(a * b);
19. 19.⚡ Which JavaScript word writes in the console? (a) let (b) alert() (c) console.log() (d) for
20. 20.⚡ What number does this code print?
    let a = 7;
    let b = 3;
    console.log(a * b);
21. 21.⚡ Which JavaScript word runs code when true? (a) let (b) console.log() (c) for (d) if
22. 22.⚡ Which tag holds JavaScript in a page? (a) <js> (b) <style> (c) <script> (d) <code>
23. 23.⚡ What does this code show?
    let name = "Riya";
    alert("Welcome, " + name + "!"); (a) Welcome, name! (b) Welcome, Riya! (c) name (d) Riya
24. 24.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 3;
    console.log(x + y); (a) 8 (b) Error (c) 53
25. 25.⚡ What number does this code print?
    let a = 6;
    let b = 31;
    console.log(a + b);
26. 26.⚡ What number does this code print?
    let a = 8;
    let b = 6;
    console.log(a * b);
27. 27.⚡ What does this code show?
    let name = "Zoya";
    console.log("Well done, " + name + "!"); (a) Well done, Zoya! (b) Well done, name! (c) name (d) Zoya
28. 28.⚡ What does this code show?
    let name = "Aman";
    console.log("Hello, " + name + "!"); (a) name (b) Aman (c) Hello, name! (d) Hello, Aman!
29. 29.⚡ What number does this code print?
    let a = 9;
    let b = 3;
    console.log(a * b);
30. 30.⚡ What number does this code print?
    let books = 6;
    books = books + 19;
    books = books - 20;
    console.log(books);
31. 31.⚡ What number does this code print?
    let a = 11;
    let b = 6;
    console.log(a * b);
32. 32.⚡ What number does this code print?
    let a = 7;
    let b = 12;
    console.log(a + b);
33. 33.⚡ What does JavaScript add to a web page? (a) the domain name (b) only colours (c) the page title (d) actions and changes
34. 34.⚡ What number does this code print?
    let a = 10;
    let b = 8;
    console.log(a + b);
35. 35.⚡ What does this code show?
    let name = "Riya";
    console.log("Hello, " + name + "!"); (a) name (b) Riya (c) Hello, Riya! (d) Hello, name!
36. 36.⚡ What number does this code print?
    let a = 5;
    let b = 23;
    console.log(a + b);
37. 37.⚡ Which JavaScript word repeats code? (a) if (b) alert() (c) let (d) for
38. 38.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 1;
    console.log(x + y); (a) Error (b) 3 (c) 21
39. 39.⚡ What number does this code print?
    let score = 19;
    score = score + 5;
    score = score - 3;
    console.log(score);
40. 40.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 4;
    console.log(x + y); (a) 7 (b) 34 (c) Error

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