JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 743 · 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.⚡ Which JavaScript word shows a pop-up box? (a) console.log() (b) alert() (c) for (d) if
2. 2.⚡ What does alert() show? (a) a table (b) a new tab (c) a picture (d) a pop-up box
3. 3.⚡ What does this code print? (Look at the quotes!)
   let x = "4";
   let y = 6;
   console.log(x + y); (a) 10 (b) Error (c) 46
4. 4.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <style> (c) <script> (d) <js>
5. 5.⚡ What does this code show?
   let name = "Arjun";
   console.log("Hi, " + name + "!"); (a) Arjun (b) Hi, name! (c) name (d) Hi, Arjun!
6. 6.⚡ What does JavaScript add to a web page? (a) only colours (b) actions and changes (c) the domain name (d) the page title
7. 7.⚡ What number does this code print?
   let a = 7;
   let b = 2;
   console.log(a * b);
8. 8.⚡ What number does this code print?
   let a = 30;
   let b = 11;
   console.log(a + b);
9. 9.⚡ What number does this code print?
   let a = 35;
   let b = 26;
   console.log(a - b);
10. 10.⚡ What number does this code print?
    let a = 2;
    let b = 3;
    console.log(a * b);
11. 11.⚡ What number does this code print?
    let a = 34;
    let b = 34;
    console.log(a - b);
12. 12.⚡ What does this code show?
    let name = "Arjun";
    alert("Hi, " + name + "!"); (a) Hi, name! (b) name (c) Hi, Arjun! (d) Arjun
13. 13.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 2;
    console.log(x + y); (a) 22 (b) Error (c) 4
14. 14.⚡ What number does this code print?
    let books = 14;
    books = books + 12;
    books = books - 15;
    console.log(books);
15. 15.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 4;
    console.log(x + y); (a) 24 (b) 6 (c) Error
16. 16.⚡ A JavaScript file usually ends with which extension? (a) .jpg (b) .css (c) .html (d) .js
17. 17.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 2;
    console.log(x + y); (a) 12 (b) Error (c) 3
18. 18.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 5;
    console.log(x + y); (a) 9 (b) Error (c) 45
19. 19.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 3;
    console.log(x + y); (a) 4 (b) 13 (c) Error
20. 20.⚡ Which JavaScript word writes in the console? (a) alert() (b) for (c) console.log() (d) if
21. 21.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 8;
    console.log(x + y); (a) Error (b) 9 (c) 18
22. 22.⚡ What number does this code print?
    let apples = 21;
    apples = apples + 14;
    apples = apples - 5;
    console.log(apples);
23. 23.⚡ Where does console.log() show its output? (a) in the address bar (b) in the console (c) on the printer (d) on the title bar
24. 24.⚡ What does this code show?
    let name = "Meera";
    console.log("Well done, " + name + "!"); (a) Well done, name! (b) name (c) Well done, Meera! (d) Meera
25. 25.⚡ What number does this code print?
    let apples = 15;
    apples = apples + 14;
    apples = apples - 27;
    console.log(apples);
26. 26.⚡ Which JavaScript word runs code when true? (a) let (b) if (c) console.log() (d) for
27. 27.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 1;
    console.log(x + y); (a) 31 (b) Error (c) 4
28. 28.⚡ What number does this code print?
    let a = 3;
    let b = 5;
    console.log(a * b);
29. 29.⚡ Which JavaScript word repeats code? (a) console.log() (b) let (c) for (d) alert()
30. 30.⚡ Which JavaScript word makes a new variable? (a) for (b) if (c) let (d) console.log()
31. 31.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 9;
    console.log(x + y); (a) 14 (b) Error (c) 59
32. 32.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 5;
    console.log(x + y); (a) 85 (b) Error (c) 13
33. 33.⚡ What number does this code print?
    let a = 4;
    let b = 4;
    console.log(a * b);
34. 34.⚡ What number does this code print?
    let a = 20;
    let b = 15;
    console.log(a + b);
35. 35.⚡ What does this code show?
    let name = "Aman";
    alert("Well done, " + name + "!"); (a) Well done, name! (b) Aman (c) Well done, Aman! (d) name
36. 36.⚡ What number does this code print?
    let apples = 15;
    apples = apples + 9;
    apples = apples - 4;
    console.log(apples);
37. 37.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 9;
    console.log(x + y); (a) 19 (b) 10 (c) Error
38. 38.⚡ What number does this code print?
    let a = 38;
    let b = 27;
    console.log(a - b);
39. 39.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 2;
    console.log(x + y); (a) 42 (b) 6 (c) Error
40. 40.⚡ What does this code show?
    let name = "Zoya";
    alert("Hi, " + name + "!"); (a) name (b) Zoya (c) Hi, name! (d) Hi, Zoya!

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