JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 194 · 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 = 9;
   let b = 8;
   console.log(a * b);
2. 2.⚡ What number does this code print?
   let a = 28;
   let b = 26;
   console.log(a + b);
3. 3.⚡ Which JavaScript word makes a new variable? (a) alert() (b) if (c) let (d) console.log()
4. 4.⚡ What does this code show?
   let name = "Kabir";
   alert("Well done, " + name + "!"); (a) Well done, name! (b) Kabir (c) name (d) Well done, Kabir!
5. 5.⚡ What does alert() show? (a) a table (b) a pop-up box (c) a picture (d) a new tab
6. 6.⚡ Which JavaScript word runs code when true? (a) for (b) if (c) let (d) console.log()
7. 7.⚡ What number does this code print?
   let a = 52;
   let b = 6;
   console.log(a + b);
8. 8.⚡ What does this code print? (Look at the quotes!)
   let x = "4";
   let y = 4;
   console.log(x + y); (a) Error (b) 8 (c) 44
9. 9.⚡ Which JavaScript word repeats code? (a) console.log() (b) for (c) if (d) let
10. 10.⚡ Which tag holds JavaScript in a page? (a) <script> (b) <js> (c) <code> (d) <style>
11. 11.⚡ What number does this code print?
    let runs = 10;
    runs = runs + 4;
    runs = runs - 10;
    console.log(runs);
12. 12.⚡ What does this code show?
    let name = "Kabir";
    alert("Hello, " + name + "!"); (a) name (b) Hello, Kabir! (c) Kabir (d) Hello, name!
13. 13.⚡ What number does this code print?
    let a = 12;
    let b = 7;
    console.log(a * b);
14. 14.⚡ What does JavaScript add to a web page? (a) the page title (b) only colours (c) the domain name (d) actions and changes
15. 15.⚡ Where does console.log() show its output? (a) in the console (b) in the address bar (c) on the printer (d) on the title bar
16. 16.⚡ What number does this code print?
    let a = 4;
    let b = 5;
    console.log(a * b);
17. 17.⚡ What does this code show?
    let name = "Meera";
    console.log("Hi, " + name + "!"); (a) Meera (b) Hi, name! (c) name (d) Hi, Meera!
18. 18.⚡ What does this code show?
    let name = "Aman";
    console.log("Welcome, " + name + "!"); (a) name (b) Welcome, name! (c) Aman (d) Welcome, Aman!
19. 19.⚡ What does this code show?
    let name = "Arjun";
    alert("Hello, " + name + "!"); (a) Hello, Arjun! (b) name (c) Hello, name! (d) Arjun
20. 20.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .jpg (c) .js (d) .html
21. 21.⚡ Which word makes a new variable? (a) make (b) let (c) put (d) give
22. 22.⚡ What number does this code print?
    let a = 60;
    let b = 7;
    console.log(a + b);
23. 23.⚡ What number does this code print?
    let a = 49;
    let b = 20;
    console.log(a + b);
24. 24.⚡ Which JavaScript word shows a pop-up box? (a) for (b) if (c) alert() (d) let
25. 25.⚡ What does this code show?
    let name = "Meera";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) Hello, Meera! (c) name (d) Meera
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 7;
    console.log(x + y); (a) 11 (b) 47 (c) Error
27. 27.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 1;
    console.log(x + y); (a) 41 (b) 5 (c) Error
28. 28.⚡ What number does this code print?
    let a = 21;
    let b = 1;
    console.log(a - b);
29. 29.⚡ What number does this code print?
    let a = 7;
    let b = 12;
    console.log(a * b);
30. 30.⚡ What number does this code print?
    let apples = 23;
    apples = apples + 16;
    apples = apples - 10;
    console.log(apples);
31. 31.⚡ What does this code show?
    let name = "Riya";
    console.log("Welcome, " + name + "!"); (a) Riya (b) Welcome, name! (c) name (d) Welcome, Riya!
32. 32.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 2;
    console.log(x + y); (a) 52 (b) Error (c) 7
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 1;
    console.log(x + y); (a) 4 (b) Error (c) 31
34. 34.⚡ What number does this code print?
    let a = 5;
    let b = 12;
    console.log(a * b);
35. 35.⚡ What number does this code print?
    let a = 21;
    let b = 7;
    console.log(a - b);
36. 36.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 4;
    console.log(x + y); (a) 94 (b) 13 (c) Error
37. 37.⚡ What does this code show?
    let name = "Arjun";
    console.log("Hello, " + name + "!"); (a) name (b) Hello, Arjun! (c) Hello, name! (d) Arjun
38. 38.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 7;
    console.log(x + y); (a) 57 (b) 12 (c) Error
39. 39.⚡ What number does this code print?
    let books = 23;
    books = books + 15;
    books = books - 36;
    console.log(books);
40. 40.⚡ What does this code show?
    let name = "Zoya";
    console.log("Welcome, " + name + "!"); (a) name (b) Zoya (c) Welcome, Zoya! (d) Welcome, name!

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