JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 177 · 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 domain name (b) only colours (c) the page title (d) actions and changes
2. 2.⚡ What number does this code print?
   let coins = 23;
   coins = coins + 9;
   coins = coins - 14;
   console.log(coins);
3. 3.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <script> (c) <js> (d) <code>
4. 4.⚡ What does this code show?
   let name = "Kabir";
   console.log("Hello, " + name + "!"); (a) Hello, name! (b) Hello, Kabir! (c) name (d) Kabir
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.⚡ What does this code print? (Look at the quotes!)
   let x = "9";
   let y = 9;
   console.log(x + y); (a) Error (b) 99 (c) 18
7. 7.⚡ What number does this code print?
   let a = 6;
   let b = 10;
   console.log(a * b);
8. 8.⚡ Which JavaScript word shows a pop-up box? (a) console.log() (b) for (c) if (d) alert()
9. 9.⚡ What number does this code print?
   let books = 13;
   books = books + 12;
   books = books - 11;
   console.log(books);
10. 10.⚡ Which word makes a new variable? (a) give (b) put (c) make (d) let
11. 11.⚡ Which JavaScript word makes a new variable? (a) for (b) if (c) let (d) console.log()
12. 12.⚡ What number does this code print?
    let a = 59;
    let b = 8;
    console.log(a + b);
13. 13.⚡ Which JavaScript word writes in the console? (a) for (b) let (c) if (d) console.log()
14. 14.⚡ What number does this code print?
    let a = 6;
    let b = 2;
    console.log(a + b);
15. 15.⚡ Where does console.log() show its output? (a) on the printer (b) in the console (c) on the title bar (d) in the address bar
16. 16.⚡ 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
17. 17.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 6;
    console.log(x + y); (a) 56 (b) 11 (c) Error
18. 18.⚡ What number does this code print?
    let runs = 19;
    runs = runs + 16;
    runs = runs - 24;
    console.log(runs);
19. 19.⚡ A JavaScript file usually ends with which extension? (a) .jpg (b) .html (c) .js (d) .css
20. 20.⚡ What does this code show?
    let name = "Riya";
    console.log("Well done, " + name + "!"); (a) Well done, name! (b) Riya (c) Well done, Riya! (d) name
21. 21.⚡ What number does this code print?
    let score = 27;
    score = score + 5;
    score = score - 28;
    console.log(score);
22. 22.⚡ What does alert() show? (a) a pop-up box (b) a table (c) a new tab (d) a picture
23. 23.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 8;
    console.log(x + y); (a) Error (b) 28 (c) 10
24. 24.⚡ What number does this code print?
    let a = 40;
    let b = 16;
    console.log(a - b);
25. 25.⚡ What number does this code print?
    let a = 9;
    let b = 4;
    console.log(a * b);
26. 26.⚡ What number does this code print?
    let a = 11;
    let b = 5;
    console.log(a * b);
27. 27.⚡ What does this code show?
    let name = "Aman";
    console.log("Welcome, " + name + "!"); (a) name (b) Welcome, name! (c) Aman (d) Welcome, Aman!
28. 28.⚡ What number does this code print?
    let runs = 26;
    runs = runs + 4;
    runs = runs - 7;
    console.log(runs);
29. 29.⚡ What number does this code print?
    let a = 39;
    let b = 22;
    console.log(a + b);
30. 30.⚡ What does this code show?
    let name = "Arjun";
    console.log("Hi, " + name + "!"); (a) Hi, name! (b) Arjun (c) Hi, Arjun! (d) name
31. 31.⚡ What number does this code print?
    let a = 6;
    let b = 4;
    console.log(a * b);
32. 32.⚡ What number does this code print?
    let a = 2;
    let b = 11;
    console.log(a * b);
33. 33.⚡ What does this code show?
    let name = "Meera";
    alert("Well done, " + name + "!"); (a) Well done, name! (b) name (c) Meera (d) Well done, Meera!
34. 34.⚡ What does this code show?
    let name = "Arjun";
    alert("Hi, " + name + "!"); (a) Arjun (b) Hi, Arjun! (c) Hi, name! (d) name
35. 35.⚡ What number does this code print?
    let a = 24;
    let b = 21;
    console.log(a + b);
36. 36.⚡ What does this code show?
    let name = "Kabir";
    alert("Hi, " + name + "!"); (a) Hi, Kabir! (b) name (c) Hi, name! (d) Kabir
37. 37.⚡ What number does this code print?
    let runs = 23;
    runs = runs + 10;
    runs = runs - 15;
    console.log(runs);
38. 38.⚡ What number does this code print?
    let a = 2;
    let b = 9;
    console.log(a * b);
39. 39.⚡ Which JavaScript word runs code when true? (a) if (b) alert() (c) for (d) let
40. 40.⚡ 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

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