JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 225 · 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 JavaScript add to a web page? (a) the domain name (b) the page title (c) only colours (d) actions and changes
2. 2.⚡ What number does this code print?
   let books = 25;
   books = books + 20;
   books = books - 24;
   console.log(books);
3. 3.⚡ What does this code print? (Look at the quotes!)
   let x = "7";
   let y = 2;
   console.log(x + y); (a) Error (b) 72 (c) 9
4. 4.⚡ What does this code print? (Look at the quotes!)
   let x = "5";
   let y = 1;
   console.log(x + y); (a) 51 (b) 6 (c) Error
5. 5.⚡ What number does this code print?
   let a = 8;
   let b = 11;
   console.log(a * b);
6. 6.⚡ Where does console.log() show its output? (a) on the title bar (b) in the address bar (c) in the console (d) on the printer
7. 7.⚡ What number does this code print?
   let marks = 6;
   marks = marks + 18;
   marks = marks - 9;
   console.log(marks);
8. 8.⚡ What does this code show?
   let name = "Riya";
   alert("Hello, " + name + "!"); (a) Hello, name! (b) Riya (c) name (d) Hello, Riya!
9. 9.⚡ What number does this code print?
   let apples = 16;
   apples = apples + 17;
   apples = apples - 8;
   console.log(apples);
10. 10.⚡ 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!
11. 11.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 6;
    console.log(x + y); (a) 96 (b) 15 (c) Error
12. 12.⚡ Which word makes a new variable? (a) let (b) put (c) make (d) give
13. 13.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 7;
    console.log(x + y); (a) 97 (b) 16 (c) Error
14. 14.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <js> (c) <code> (d) <script>
15. 15.⚡ What number does this code print?
    let a = 31;
    let b = 34;
    console.log(a + b);
16. 16.⚡ Which JavaScript word writes in the console? (a) for (b) if (c) console.log() (d) alert()
17. 17.⚡ Which JavaScript word makes a new variable? (a) alert() (b) if (c) let (d) console.log()
18. 18.⚡ What does alert() show? (a) a table (b) a new tab (c) a pop-up box (d) a picture
19. 19.⚡ What does this code show?
    let name = "Aman";
    console.log("Hello, " + name + "!"); (a) Hello, Aman! (b) Hello, name! (c) name (d) Aman
20. 20.⚡ What number does this code print?
    let a = 26;
    let b = 25;
    console.log(a - b);
21. 21.⚡ What number does this code print?
    let coins = 24;
    coins = coins + 15;
    coins = coins - 35;
    console.log(coins);
22. 22.⚡ What does this code show?
    let name = "Arjun";
    alert("Well done, " + name + "!"); (a) Well done, name! (b) Well done, Arjun! (c) name (d) Arjun
23. 23.⚡ What number does this code print?
    let apples = 16;
    apples = apples + 8;
    apples = apples - 18;
    console.log(apples);
24. 24.⚡ What number does this code print?
    let a = 7;
    let b = 5;
    console.log(a * b);
25. 25.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 5;
    console.log(x + y); (a) 75 (b) Error (c) 12
26. 26.⚡ What does this code show?
    let name = "Arjun";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) Arjun (c) Hello, Arjun! (d) name
27. 27.⚡ Which JavaScript word shows a pop-up box? (a) console.log() (b) alert() (c) if (d) let
28. 28.⚡ A JavaScript file usually ends with which extension? (a) .jpg (b) .html (c) .js (d) .css
29. 29.⚡ Which JavaScript word repeats code? (a) console.log() (b) alert() (c) let (d) for
30. 30.⚡ What does this code show?
    let name = "Zoya";
    console.log("Welcome, " + name + "!"); (a) name (b) Welcome, Zoya! (c) Zoya (d) Welcome, name!
31. 31.⚡ What number does this code print?
    let books = 30;
    books = books + 5;
    books = books - 30;
    console.log(books);
32. 32.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 2;
    console.log(x + y); (a) 42 (b) Error (c) 6
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 5;
    console.log(x + y); (a) 7 (b) Error (c) 25
34. 34.⚡ What number does this code print?
    let a = 12;
    let b = 12;
    console.log(a * b);
35. 35.⚡ What number does this code print?
    let marks = 19;
    marks = marks + 9;
    marks = marks - 8;
    console.log(marks);
36. 36.⚡ What does this code show?
    let name = "Zoya";
    alert("Welcome, " + name + "!"); (a) name (b) Welcome, Zoya! (c) Welcome, name! (d) Zoya
37. 37.⚡ What does this code show?
    let name = "Aman";
    alert("Hi, " + name + "!"); (a) name (b) Hi, name! (c) Hi, Aman! (d) Aman
38. 38.⚡ What number does this code print?
    let a = 3;
    let b = 6;
    console.log(a * b);
39. 39.⚡ What does this code show?
    let name = "Aman";
    alert("Well done, " + name + "!"); (a) Well done, name! (b) name (c) Aman (d) Well done, Aman!
40. 40.⚡ What number does this code print?
    let books = 7;
    books = books + 4;
    books = books - 4;
    console.log(books);

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