JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 63 · 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 print? (Look at the quotes!)
   let x = "4";
   let y = 7;
   console.log(x + y); (a) 11 (b) Error (c) 47
2. 2.⚡ What number does this code print?
   let a = 38;
   let b = 36;
   console.log(a - b);
3. 3.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) console.log() (c) for (d) let
4. 4.⚡ Which word makes a new variable? (a) let (b) put (c) make (d) give
5. 5.⚡ What does this code print? (Look at the quotes!)
   let x = "6";
   let y = 7;
   console.log(x + y); (a) Error (b) 13 (c) 67
6. 6.⚡ Which JavaScript word runs code when true? (a) console.log() (b) alert() (c) let (d) if
7. 7.⚡ What does this code print? (Look at the quotes!)
   let x = "4";
   let y = 1;
   console.log(x + y); (a) 5 (b) 41 (c) Error
8. 8.⚡ What number does this code print?
   let a = 54;
   let b = 8;
   console.log(a + b);
9. 9.⚡ What number does this code print?
   let apples = 24;
   apples = apples + 6;
   apples = apples - 29;
   console.log(apples);
10. 10.⚡ What number does this code print?
    let a = 6;
    let b = 6;
    console.log(a * b);
11. 11.⚡ What number does this code print?
    let a = 26;
    let b = 17;
    console.log(a + b);
12. 12.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 8;
    console.log(x + y); (a) 16 (b) Error (c) 88
13. 13.⚡ What number does this code print?
    let a = 50;
    let b = 29;
    console.log(a + b);
14. 14.⚡ What number does this code print?
    let a = 14;
    let b = 23;
    console.log(a + b);
15. 15.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 8;
    console.log(x + y); (a) 18 (b) 9 (c) Error
16. 16.⚡ Which tag holds JavaScript in a page? (a) <js> (b) <script> (c) <style> (d) <code>
17. 17.⚡ What number does this code print?
    let books = 5;
    books = books + 15;
    books = books - 4;
    console.log(books);
18. 18.⚡ What number does this code print?
    let score = 17;
    score = score + 2;
    score = score - 5;
    console.log(score);
19. 19.⚡ What number does this code print?
    let runs = 20;
    runs = runs + 20;
    runs = runs - 11;
    console.log(runs);
20. 20.⚡ What does alert() show? (a) a pop-up box (b) a new tab (c) a picture (d) a table
21. 21.⚡ What does this code show?
    let name = "Arjun";
    console.log("Welcome, " + name + "!"); (a) Arjun (b) name (c) Welcome, name! (d) Welcome, Arjun!
22. 22.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 8;
    console.log(x + y); (a) 15 (b) 78 (c) Error
23. 23.⚡ What does this code show?
    let name = "Kabir";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) Kabir (c) Hello, Kabir! (d) name
24. 24.⚡ What number does this code print?
    let score = 19;
    score = score + 17;
    score = score - 12;
    console.log(score);
25. 25.⚡ Which JavaScript word repeats code? (a) alert() (b) for (c) if (d) console.log()
26. 26.⚡ Which JavaScript word writes in the console? (a) alert() (b) console.log() (c) if (d) for
27. 27.⚡ What does JavaScript add to a web page? (a) only colours (b) the page title (c) the domain name (d) actions and changes
28. 28.⚡ What does this code show?
    let name = "Zoya";
    console.log("Welcome, " + name + "!"); (a) Zoya (b) name (c) Welcome, name! (d) Welcome, Zoya!
29. 29.⚡ What does this code show?
    let name = "Aman";
    alert("Hello, " + name + "!"); (a) Hello, Aman! (b) name (c) Hello, name! (d) Aman
30. 30.⚡ What does this code show?
    let name = "Aman";
    console.log("Hello, " + name + "!"); (a) Hello, Aman! (b) name (c) Hello, name! (d) Aman
31. 31.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 5;
    console.log(x + y); (a) Error (b) 6 (c) 15
32. 32.⚡ What number does this code print?
    let a = 51;
    let b = 5;
    console.log(a - b);
33. 33.⚡ What does this code show?
    let name = "Meera";
    alert("Well done, " + name + "!"); (a) name (b) Meera (c) Well done, Meera! (d) Well done, name!
34. 34.⚡ What number does this code print?
    let apples = 17;
    apples = apples + 3;
    apples = apples - 20;
    console.log(apples);
35. 35.⚡ 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
36. 36.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 4;
    console.log(x + y); (a) 10 (b) 64 (c) Error
37. 37.⚡ Which JavaScript word makes a new variable? (a) alert() (b) for (c) let (d) if
38. 38.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .jpg (c) .html (d) .js
39. 39.⚡ What number does this code print?
    let a = 22;
    let b = 14;
    console.log(a + b);
40. 40.⚡ Where does console.log() show its output? (a) on the title bar (b) on the printer (c) in the address bar (d) in the console

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