JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 100 · 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 a = 24;
   let b = 17;
   console.log(a - b);
2. 2.⚡ Which JavaScript word repeats code? (a) alert() (b) console.log() (c) if (d) for
3. 3.⚡ Which word makes a new variable? (a) make (b) put (c) let (d) give
4. 4.⚡ What number does this code print?
   let a = 6;
   let b = 4;
   console.log(a * b);
5. 5.⚡ What number does this code print?
   let coins = 9;
   coins = coins + 19;
   coins = coins - 12;
   console.log(coins);
6. 6.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <code> (c) <script> (d) <js>
7. 7.⚡ What number does this code print?
   let marks = 11;
   marks = marks + 11;
   marks = marks - 10;
   console.log(marks);
8. 8.⚡ Which JavaScript word makes a new variable? (a) alert() (b) if (c) for (d) let
9. 9.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .js (c) .css (d) .jpg
10. 10.⚡ What does this code show?
    let name = "Aman";
    console.log("Hi, " + name + "!"); (a) Hi, Aman! (b) Aman (c) Hi, name! (d) name
11. 11.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 8;
    console.log(x + y); (a) 10 (b) 28 (c) Error
12. 12.⚡ Where does console.log() show its output? (a) in the console (b) on the printer (c) in the address bar (d) on the title bar
13. 13.⚡ What number does this code print?
    let coins = 27;
    coins = coins + 7;
    coins = coins - 22;
    console.log(coins);
14. 14.⚡ What number does this code print?
    let score = 18;
    score = score + 13;
    score = score - 4;
    console.log(score);
15. 15.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 8;
    console.log(x + y); (a) 17 (b) Error (c) 98
16. 16.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 3;
    console.log(x + y); (a) Error (b) 10 (c) 73
17. 17.⚡ What does this code show?
    let name = "Aman";
    alert("Well done, " + name + "!"); (a) Well done, name! (b) name (c) Aman (d) Well done, Aman!
18. 18.⚡ What number does this code print?
    let a = 10;
    let b = 9;
    console.log(a * b);
19. 19.⚡ What number does this code print?
    let marks = 16;
    marks = marks + 18;
    marks = marks - 3;
    console.log(marks);
20. 20.⚡ What does alert() show? (a) a picture (b) a table (c) a new tab (d) a pop-up box
21. 21.⚡ Which JavaScript word shows a pop-up box? (a) console.log() (b) if (c) let (d) alert()
22. 22.⚡ What does JavaScript add to a web page? (a) only colours (b) the page title (c) actions and changes (d) the domain name
23. 23.⚡ What number does this code print?
    let a = 46;
    let b = 10;
    console.log(a + b);
24. 24.⚡ 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!
25. 25.⚡ What number does this code print?
    let a = 36;
    let b = 4;
    console.log(a - b);
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 9;
    console.log(x + y); (a) 14 (b) 59 (c) Error
27. 27.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 2;
    console.log(x + y); (a) 3 (b) 12 (c) Error
28. 28.⚡ What number does this code print?
    let a = 6;
    let b = 16;
    console.log(a + b);
29. 29.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 5;
    console.log(x + y); (a) 9 (b) Error (c) 45
30. 30.⚡ Which JavaScript word runs code when true? (a) alert() (b) let (c) console.log() (d) if
31. 31.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 8;
    console.log(x + y); (a) Error (b) 18 (c) 9
32. 32.⚡ What number does this code print?
    let a = 29;
    let b = 19;
    console.log(a - b);
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 4;
    console.log(x + y); (a) Error (b) 7 (c) 34
34. 34.⚡ What does this code show?
    let name = "Aman";
    alert("Hello, " + name + "!"); (a) Aman (b) Hello, name! (c) name (d) Hello, Aman!
35. 35.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 6;
    console.log(x + y); (a) Error (b) 76 (c) 13
36. 36.⚡ What number does this code print?
    let a = 20;
    let b = 4;
    console.log(a - b);
37. 37.⚡ What does this code show?
    let name = "Aman";
    console.log("Hello, " + name + "!"); (a) Hello, Aman! (b) Hello, name! (c) name (d) Aman
38. 38.⚡ What does this code show?
    let name = "Kabir";
    console.log("Welcome, " + name + "!"); (a) Welcome, Kabir! (b) name (c) Welcome, name! (d) Kabir
39. 39.⚡ What number does this code print?
    let books = 20;
    books = books + 14;
    books = books - 33;
    console.log(books);
40. 40.⚡ What number does this code print?
    let runs = 28;
    runs = runs + 11;
    runs = runs - 34;
    console.log(runs);

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