JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 420 · 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.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .jpg (c) .js (d) .css
2. 2.⚡ What does alert() show? (a) a new tab (b) a table (c) a pop-up box (d) a picture
3. 3.⚡ Which word makes a new variable? (a) let (b) make (c) give (d) put
4. 4.⚡ Which JavaScript word shows a pop-up box? (a) if (b) for (c) alert() (d) let
5. 5.⚡ What does this code print? (Look at the quotes!)
   let x = "2";
   let y = 2;
   console.log(x + y); (a) 22 (b) 4 (c) Error
6. 6.⚡ Which JavaScript word writes in the console? (a) let (b) alert() (c) if (d) console.log()
7. 7.⚡ What number does this code print?
   let a = 46;
   let b = 29;
   console.log(a + b);
8. 8.⚡ What number does this code print?
   let a = 25;
   let b = 1;
   console.log(a - b);
9. 9.⚡ What does this code show?
   let name = "Arjun";
   alert("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Arjun (d) Hello, Arjun!
10. 10.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 3;
    console.log(x + y); (a) 13 (b) Error (c) 4
11. 11.⚡ What number does this code print?
    let a = 9;
    let b = 7;
    console.log(a + b);
12. 12.⚡ Which JavaScript word makes a new variable? (a) if (b) let (c) console.log() (d) for
13. 13.⚡ What number does this code print?
    let score = 13;
    score = score + 20;
    score = score - 18;
    console.log(score);
14. 14.⚡ Which JavaScript word repeats code? (a) let (b) if (c) for (d) console.log()
15. 15.⚡ What does this code show?
    let name = "Riya";
    console.log("Hello, " + name + "!"); (a) name (b) Riya (c) Hello, name! (d) Hello, Riya!
16. 16.⚡ What does this code show?
    let name = "Aman";
    console.log("Hello, " + name + "!"); (a) Aman (b) Hello, Aman! (c) Hello, name! (d) name
17. 17.⚡ What does this code show?
    let name = "Aman";
    console.log("Well done, " + name + "!"); (a) Aman (b) name (c) Well done, Aman! (d) Well done, name!
18. 18.⚡ Which JavaScript word runs code when true? (a) alert() (b) if (c) let (d) for
19. 19.⚡ What number does this code print?
    let marks = 5;
    marks = marks + 9;
    marks = marks - 9;
    console.log(marks);
20. 20.⚡ What number does this code print?
    let score = 19;
    score = score + 6;
    score = score - 22;
    console.log(score);
21. 21.⚡ What number does this code print?
    let a = 2;
    let b = 10;
    console.log(a * b);
22. 22.⚡ What does this code show?
    let name = "Zoya";
    console.log("Well done, " + name + "!"); (a) Zoya (b) Well done, Zoya! (c) Well done, name! (d) name
23. 23.⚡ What number does this code print?
    let a = 60;
    let b = 3;
    console.log(a + b);
24. 24.⚡ What does this code show?
    let name = "Kabir";
    alert("Well done, " + name + "!"); (a) Kabir (b) Well done, name! (c) name (d) Well done, Kabir!
25. 25.⚡ What number does this code print?
    let coins = 6;
    coins = coins + 14;
    coins = coins - 15;
    console.log(coins);
26. 26.⚡ What number does this code print?
    let score = 14;
    score = score + 2;
    score = score - 1;
    console.log(score);
27. 27.⚡ Which tag holds JavaScript in a page? (a) <script> (b) <code> (c) <js> (d) <style>
28. 28.⚡ What does JavaScript add to a web page? (a) the page title (b) the domain name (c) actions and changes (d) only colours
29. 29.⚡ What number does this code print?
    let a = 46;
    let b = 26;
    console.log(a + b);
30. 30.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 6;
    console.log(x + y); (a) 10 (b) 46 (c) Error
31. 31.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 4;
    console.log(x + y); (a) Error (b) 24 (c) 6
32. 32.⚡ What number does this code print?
    let marks = 16;
    marks = marks + 15;
    marks = marks - 1;
    console.log(marks);
33. 33.⚡ What does this code show?
    let name = "Aman";
    alert("Well done, " + name + "!"); (a) name (b) Aman (c) Well done, name! (d) Well done, Aman!
34. 34.⚡ What number does this code print?
    let a = 41;
    let b = 9;
    console.log(a - b);
35. 35.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 8;
    console.log(x + y); (a) 9 (b) 18 (c) Error
36. 36.⚡ What does this code show?
    let name = "Meera";
    console.log("Well done, " + name + "!"); (a) Meera (b) Well done, Meera! (c) name (d) Well done, name!
37. 37.⚡ 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
38. 38.⚡ What number does this code print?
    let a = 12;
    let b = 9;
    console.log(a * b);
39. 39.⚡ What number does this code print?
    let a = 49;
    let b = 39;
    console.log(a - b);
40. 40.⚡ What does this code show?
    let name = "Aman";
    console.log("Welcome, " + name + "!"); (a) Aman (b) name (c) Welcome, name! (d) Welcome, Aman!

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