JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 766 · 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 page title (b) the domain name (c) only colours (d) actions and changes
2. 2.⚡ Which JavaScript word writes in the console? (a) alert() (b) let (c) console.log() (d) if
3. 3.⚡ What does this code print? (Look at the quotes!)
   let x = "4";
   let y = 3;
   console.log(x + y); (a) 7 (b) Error (c) 43
4. 4.⚡ What number does this code print?
   let apples = 27;
   apples = apples + 17;
   apples = apples - 4;
   console.log(apples);
5. 5.⚡ What number does this code print?
   let books = 6;
   books = books + 8;
   books = books - 3;
   console.log(books);
6. 6.⚡ What number does this code print?
   let a = 46;
   let b = 29;
   console.log(a - b);
7. 7.⚡ What does this code print? (Look at the quotes!)
   let x = "3";
   let y = 1;
   console.log(x + y); (a) 31 (b) 4 (c) Error
8. 8.⚡ What does this code print? (Look at the quotes!)
   let x = "1";
   let y = 5;
   console.log(x + y); (a) Error (b) 15 (c) 6
9. 9.⚡ Which JavaScript word shows a pop-up box? (a) console.log() (b) for (c) alert() (d) if
10. 10.⚡ Which word makes a new variable? (a) put (b) let (c) give (d) make
11. 11.⚡ Which JavaScript word repeats code? (a) alert() (b) console.log() (c) if (d) for
12. 12.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <js> (c) <script> (d) <code>
13. 13.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 5;
    console.log(x + y); (a) 11 (b) 65 (c) Error
14. 14.⚡ What number does this code print?
    let books = 24;
    books = books + 20;
    books = books - 32;
    console.log(books);
15. 15.⚡ What number does this code print?
    let a = 8;
    let b = 11;
    console.log(a * b);
16. 16.⚡ What does this code show?
    let name = "Arjun";
    console.log("Hi, " + name + "!"); (a) Arjun (b) name (c) Hi, Arjun! (d) Hi, name!
17. 17.⚡ Which JavaScript word runs code when true? (a) if (b) console.log() (c) let (d) for
18. 18.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .html (c) .jpg (d) .js
19. 19.⚡ What number does this code print?
    let a = 43;
    let b = 28;
    console.log(a - b);
20. 20.⚡ What does this code show?
    let name = "Arjun";
    console.log("Welcome, " + name + "!"); (a) name (b) Welcome, name! (c) Welcome, Arjun! (d) Arjun
21. 21.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 1;
    console.log(x + y); (a) 6 (b) Error (c) 51
22. 22.⚡ What number does this code print?
    let score = 23;
    score = score + 8;
    score = score - 1;
    console.log(score);
23. 23.⚡ What does alert() show? (a) a table (b) a new tab (c) a pop-up box (d) a picture
24. 24.⚡ What does this code show?
    let name = "Zoya";
    alert("Well done, " + name + "!"); (a) name (b) Well done, Zoya! (c) Zoya (d) Well done, name!
25. 25.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 2;
    console.log(x + y); (a) 82 (b) Error (c) 10
26. 26.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hi, " + name + "!"); (a) name (b) Hi, name! (c) Hi, Kabir! (d) Kabir
27. 27.⚡ What number does this code print?
    let runs = 5;
    runs = runs + 13;
    runs = runs - 6;
    console.log(runs);
28. 28.⚡ What number does this code print?
    let a = 5;
    let b = 10;
    console.log(a * b);
29. 29.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 9;
    console.log(x + y); (a) 29 (b) 11 (c) Error
30. 30.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 5;
    console.log(x + y); (a) 8 (b) Error (c) 35
31. 31.⚡ What number does this code print?
    let a = 30;
    let b = 3;
    console.log(a + b);
32. 32.⚡ What number does this code print?
    let a = 27;
    let b = 27;
    console.log(a - b);
33. 33.⚡ What number does this code print?
    let a = 6;
    let b = 25;
    console.log(a + b);
34. 34.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 3;
    console.log(x + y); (a) 73 (b) Error (c) 10
35. 35.⚡ What number does this code print?
    let coins = 8;
    coins = coins + 19;
    coins = coins - 9;
    console.log(coins);
36. 36.⚡ Where does console.log() show its output? (a) in the console (b) on the title bar (c) on the printer (d) in the address bar
37. 37.⚡ 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
38. 38.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 1;
    console.log(x + y); (a) Error (b) 5 (c) 41
39. 39.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 2;
    console.log(x + y); (a) Error (b) 7 (c) 52
40. 40.⚡ What does this code show?
    let name = "Aman";
    console.log("Hello, " + name + "!"); (a) Hello, Aman! (b) Aman (c) Hello, name! (d) name

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