JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 622 · 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 = 14;
   let b = 10;
   console.log(a - b);
2. 2.⚡ What does this code print? (Look at the quotes!)
   let x = "4";
   let y = 8;
   console.log(x + y); (a) 48 (b) Error (c) 12
3. 3.⚡ What does JavaScript add to a web page? (a) actions and changes (b) the domain name (c) only colours (d) the page title
4. 4.⚡ What number does this code print?
   let a = 7;
   let b = 6;
   console.log(a * b);
5. 5.⚡ What number does this code print?
   let a = 53;
   let b = 25;
   console.log(a + b);
6. 6.⚡ What number does this code print?
   let a = 25;
   let b = 16;
   console.log(a + b);
7. 7.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .jpg (c) .js (d) .css
8. 8.⚡ What number does this code print?
   let a = 35;
   let b = 12;
   console.log(a - b);
9. 9.⚡ Which JavaScript word shows a pop-up box? (a) console.log() (b) let (c) if (d) alert()
10. 10.⚡ Which JavaScript word writes in the console? (a) console.log() (b) let (c) for (d) if
11. 11.⚡ What number does this code print?
    let books = 5;
    books = books + 20;
    books = books - 1;
    console.log(books);
12. 12.⚡ What does this code show?
    let name = "Meera";
    alert("Welcome, " + name + "!"); (a) Welcome, Meera! (b) Meera (c) Welcome, name! (d) name
13. 13.⚡ What does this code show?
    let name = "Meera";
    alert("Hello, " + name + "!"); (a) name (b) Hello, name! (c) Meera (d) Hello, Meera!
14. 14.⚡ What does this code show?
    let name = "Meera";
    console.log("Welcome, " + name + "!"); (a) Welcome, Meera! (b) name (c) Welcome, name! (d) Meera
15. 15.⚡ What number does this code print?
    let score = 20;
    score = score + 10;
    score = score - 27;
    console.log(score);
16. 16.⚡ What number does this code print?
    let a = 23;
    let b = 10;
    console.log(a - b);
17. 17.⚡ What number does this code print?
    let runs = 21;
    runs = runs + 5;
    runs = runs - 25;
    console.log(runs);
18. 18.⚡ Which tag holds JavaScript in a page? (a) <script> (b) <code> (c) <js> (d) <style>
19. 19.⚡ What number does this code print?
    let a = 37;
    let b = 31;
    console.log(a - b);
20. 20.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 2;
    console.log(x + y); (a) 72 (b) Error (c) 9
21. 21.⚡ 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
22. 22.⚡ What number does this code print?
    let a = 11;
    let b = 24;
    console.log(a + b);
23. 23.⚡ What number does this code print?
    let books = 8;
    books = books + 14;
    books = books - 2;
    console.log(books);
24. 24.⚡ What number does this code print?
    let a = 47;
    let b = 35;
    console.log(a - b);
25. 25.⚡ What does this code show?
    let name = "Kabir";
    console.log("Well done, " + name + "!"); (a) Well done, Kabir! (b) name (c) Well done, name! (d) Kabir
26. 26.⚡ What does this code show?
    let name = "Aman";
    alert("Welcome, " + name + "!"); (a) Aman (b) name (c) Welcome, Aman! (d) Welcome, name!
27. 27.⚡ What number does this code print?
    let a = 4;
    let b = 10;
    console.log(a * b);
28. 28.⚡ Which word makes a new variable? (a) let (b) put (c) make (d) give
29. 29.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 6;
    console.log(x + y); (a) 26 (b) 8 (c) Error
30. 30.⚡ What does alert() show? (a) a new tab (b) a picture (c) a table (d) a pop-up box
31. 31.⚡ Which JavaScript word runs code when true? (a) let (b) console.log() (c) alert() (d) if
32. 32.⚡ What does this code show?
    let name = "Aman";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) name (c) Welcome, Aman! (d) Aman
33. 33.⚡ What does this code show?
    let name = "Arjun";
    console.log("Hello, " + name + "!"); (a) Hello, Arjun! (b) Arjun (c) Hello, name! (d) name
34. 34.⚡ What does this code show?
    let name = "Aman";
    console.log("Well done, " + name + "!"); (a) Aman (b) Well done, name! (c) name (d) Well done, Aman!
35. 35.⚡ What number does this code print?
    let a = 12;
    let b = 13;
    console.log(a + b);
36. 36.⚡ What number does this code print?
    let apples = 20;
    apples = apples + 10;
    apples = apples - 30;
    console.log(apples);
37. 37.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hi, " + name + "!"); (a) Hi, Kabir! (b) Hi, name! (c) name (d) Kabir
38. 38.⚡ Which JavaScript word makes a new variable? (a) if (b) alert() (c) console.log() (d) let
39. 39.⚡ What number does this code print?
    let a = 28;
    let b = 31;
    console.log(a + b);
40. 40.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 5;
    console.log(x + y); (a) Error (b) 9 (c) 45

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