JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 969 · 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.⚡ Which JavaScript word makes a new variable? (a) console.log() (b) alert() (c) for (d) let
2. 2.⚡ Which JavaScript word repeats code? (a) let (b) console.log() (c) for (d) alert()
3. 3.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) if (c) for (d) console.log()
4. 4.⚡ What number does this code print?
   let apples = 26;
   apples = apples + 14;
   apples = apples - 32;
   console.log(apples);
5. 5.⚡ What number does this code print?
   let a = 46;
   let b = 29;
   console.log(a + b);
6. 6.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .html (c) .js (d) .jpg
7. 7.⚡ What number does this code print?
   let a = 16;
   let b = 9;
   console.log(a + b);
8. 8.⚡ What does this code print? (Look at the quotes!)
   let x = "6";
   let y = 8;
   console.log(x + y); (a) 68 (b) Error (c) 14
9. 9.⚡ What number does this code print?
   let a = 8;
   let b = 6;
   console.log(a - b);
10. 10.⚡ What number does this code print?
    let apples = 26;
    apples = apples + 19;
    apples = apples - 9;
    console.log(apples);
11. 11.⚡ Where does console.log() show its output? (a) in the console (b) on the printer (c) on the title bar (d) in the address bar
12. 12.⚡ What does JavaScript add to a web page? (a) the domain name (b) actions and changes (c) only colours (d) the page title
13. 13.⚡ What number does this code print?
    let books = 17;
    books = books + 3;
    books = books - 13;
    console.log(books);
14. 14.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 6;
    console.log(x + y); (a) 14 (b) Error (c) 86
15. 15.⚡ What number does this code print?
    let apples = 25;
    apples = apples + 3;
    apples = apples - 28;
    console.log(apples);
16. 16.⚡ 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
17. 17.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 8;
    console.log(x + y); (a) 16 (b) 88 (c) Error
18. 18.⚡ What does this code show?
    let name = "Aman";
    console.log("Hello, " + name + "!"); (a) Aman (b) Hello, Aman! (c) name (d) Hello, name!
19. 19.⚡ What number does this code print?
    let a = 30;
    let b = 4;
    console.log(a - b);
20. 20.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <style> (c) <js> (d) <script>
21. 21.⚡ Which word makes a new variable? (a) make (b) give (c) put (d) let
22. 22.⚡ What does this code show?
    let name = "Riya";
    alert("Welcome, " + name + "!"); (a) Welcome, Riya! (b) Welcome, name! (c) name (d) Riya
23. 23.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 1;
    console.log(x + y); (a) Error (b) 9 (c) 81
24. 24.⚡ What does this code show?
    let name = "Arjun";
    console.log("Hi, " + name + "!"); (a) Arjun (b) Hi, Arjun! (c) Hi, name! (d) name
25. 25.⚡ What number does this code print?
    let a = 44;
    let b = 4;
    console.log(a + b);
26. 26.⚡ What does this code show?
    let name = "Meera";
    console.log("Well done, " + name + "!"); (a) Well done, name! (b) Well done, Meera! (c) Meera (d) name
27. 27.⚡ What number does this code print?
    let marks = 20;
    marks = marks + 11;
    marks = marks - 10;
    console.log(marks);
28. 28.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 2;
    console.log(x + y); (a) 10 (b) 82 (c) Error
29. 29.⚡ What number does this code print?
    let a = 52;
    let b = 39;
    console.log(a + b);
30. 30.⚡ 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
31. 31.⚡ What number does this code print?
    let a = 33;
    let b = 7;
    console.log(a - b);
32. 32.⚡ What does this code show?
    let name = "Arjun";
    alert("Hi, " + name + "!"); (a) Arjun (b) Hi, name! (c) name (d) Hi, Arjun!
33. 33.⚡ What number does this code print?
    let a = 56;
    let b = 18;
    console.log(a + b);
34. 34.⚡ Which JavaScript word runs code when true? (a) if (b) for (c) alert() (d) let
35. 35.⚡ What does this code show?
    let name = "Meera";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) Meera (c) Welcome, Meera! (d) name
36. 36.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 2;
    console.log(x + y); (a) 8 (b) 62 (c) Error
37. 37.⚡ What number does this code print?
    let marks = 20;
    marks = marks + 9;
    marks = marks - 14;
    console.log(marks);
38. 38.⚡ What does alert() show? (a) a new tab (b) a table (c) a picture (d) a pop-up box
39. 39.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 3;
    console.log(x + y); (a) Error (b) 63 (c) 9
40. 40.⚡ What number does this code print?
    let coins = 25;
    coins = coins + 13;
    coins = coins - 13;
    console.log(coins);

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