JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 400 · 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 marks = 25;
   marks = marks + 5;
   marks = marks - 6;
   console.log(marks);
2. 2.⚡ What number does this code print?
   let score = 5;
   score = score + 12;
   score = score - 3;
   console.log(score);
3. 3.⚡ What number does this code print?
   let a = 37;
   let b = 10;
   console.log(a - b);
4. 4.⚡ What does this code show?
   let name = "Meera";
   alert("Well done, " + name + "!"); (a) name (b) Well done, name! (c) Well done, Meera! (d) Meera
5. 5.⚡ What does this code print? (Look at the quotes!)
   let x = "9";
   let y = 5;
   console.log(x + y); (a) 14 (b) 95 (c) Error
6. 6.⚡ Which JavaScript word shows a pop-up box? (a) for (b) if (c) console.log() (d) alert()
7. 7.⚡ Which JavaScript word makes a new variable? (a) alert() (b) for (c) if (d) let
8. 8.⚡ What does this code print? (Look at the quotes!)
   let x = "3";
   let y = 7;
   console.log(x + y); (a) Error (b) 10 (c) 37
9. 9.⚡ Which word makes a new variable? (a) give (b) make (c) let (d) put
10. 10.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <js> (c) <script> (d) <style>
11. 11.⚡ Which JavaScript word writes in the console? (a) let (b) alert() (c) console.log() (d) for
12. 12.⚡ What number does this code print?
    let apples = 9;
    apples = apples + 13;
    apples = apples - 9;
    console.log(apples);
13. 13.⚡ What does this code show?
    let name = "Aman";
    alert("Hello, " + name + "!"); (a) name (b) Hello, Aman! (c) Aman (d) Hello, name!
14. 14.⚡ What number does this code print?
    let marks = 28;
    marks = marks + 4;
    marks = marks - 31;
    console.log(marks);
15. 15.⚡ What does this code show?
    let name = "Zoya";
    console.log("Well done, " + name + "!"); (a) Well done, name! (b) Well done, Zoya! (c) Zoya (d) name
16. 16.⚡ What does alert() show? (a) a picture (b) a table (c) a pop-up box (d) a new tab
17. 17.⚡ What does this code show?
    let name = "Zoya";
    alert("Well done, " + name + "!"); (a) Well done, name! (b) Well done, Zoya! (c) name (d) Zoya
18. 18.⚡ Which JavaScript word runs code when true? (a) alert() (b) if (c) for (d) console.log()
19. 19.⚡ Which JavaScript word repeats code? (a) for (b) if (c) console.log() (d) let
20. 20.⚡ What number does this code print?
    let a = 56;
    let b = 22;
    console.log(a + b);
21. 21.⚡ What number does this code print?
    let runs = 10;
    runs = runs + 9;
    runs = runs - 2;
    console.log(runs);
22. 22.⚡ What number does this code print?
    let a = 23;
    let b = 40;
    console.log(a + b);
23. 23.⚡ 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
24. 24.⚡ What does this code show?
    let name = "Arjun";
    console.log("Hi, " + name + "!"); (a) Arjun (b) Hi, Arjun! (c) name (d) Hi, name!
25. 25.⚡ What does this code show?
    let name = "Aman";
    console.log("Well done, " + name + "!"); (a) Well done, name! (b) Well done, Aman! (c) Aman (d) name
26. 26.⚡ What does this code show?
    let name = "Aman";
    alert("Hi, " + name + "!"); (a) Hi, Aman! (b) Hi, name! (c) name (d) Aman
27. 27.⚡ 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
28. 28.⚡ What does this code show?
    let name = "Zoya";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) Zoya (c) name (d) Hello, Zoya!
29. 29.⚡ What number does this code print?
    let a = 3;
    let b = 2;
    console.log(a * b);
30. 30.⚡ What number does this code print?
    let a = 32;
    let b = 16;
    console.log(a - b);
31. 31.⚡ What does this code show?
    let name = "Meera";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) Meera (c) Hello, Meera! (d) name
32. 32.⚡ What number does this code print?
    let a = 10;
    let b = 28;
    console.log(a + b);
33. 33.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .jpg (c) .css (d) .js
34. 34.⚡ What number does this code print?
    let a = 26;
    let b = 11;
    console.log(a - b);
35. 35.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 2;
    console.log(x + y); (a) 4 (b) Error (c) 22
36. 36.⚡ What number does this code print?
    let a = 20;
    let b = 2;
    console.log(a + b);
37. 37.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 7;
    console.log(x + y); (a) 16 (b) 97 (c) Error
38. 38.⚡ What number does this code print?
    let books = 12;
    books = books + 15;
    books = books - 2;
    console.log(books);
39. 39.⚡ What does JavaScript add to a web page? (a) only colours (b) the domain name (c) the page title (d) actions and changes
40. 40.⚡ What number does this code print?
    let apples = 13;
    apples = apples + 7;
    apples = apples - 4;
    console.log(apples);

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