JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 635 · 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 runs code when true? (a) let (b) alert() (c) console.log() (d) if
2. 2.⚡ What does this code print? (Look at the quotes!)
   let x = "8";
   let y = 7;
   console.log(x + y); (a) 87 (b) Error (c) 15
3. 3.⚡ Where does console.log() show its output? (a) in the address bar (b) on the printer (c) on the title bar (d) in the console
4. 4.⚡ What does this code print? (Look at the quotes!)
   let x = "6";
   let y = 1;
   console.log(x + y); (a) 61 (b) Error (c) 7
5. 5.⚡ What number does this code print?
   let apples = 12;
   apples = apples + 18;
   apples = apples - 15;
   console.log(apples);
6. 6.⚡ What number does this code print?
   let a = 8;
   let b = 12;
   console.log(a * b);
7. 7.⚡ Which word makes a new variable? (a) put (b) give (c) let (d) make
8. 8.⚡ What number does this code print?
   let apples = 6;
   apples = apples + 4;
   apples = apples - 8;
   console.log(apples);
9. 9.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) let (c) if (d) console.log()
10. 10.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 6;
    console.log(x + y); (a) 36 (b) 9 (c) Error
11. 11.⚡ What number does this code print?
    let a = 6;
    let b = 12;
    console.log(a * b);
12. 12.⚡ What number does this code print?
    let a = 60;
    let b = 40;
    console.log(a - b);
13. 13.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .jpg (c) .css (d) .html
14. 14.⚡ What number does this code print?
    let score = 30;
    score = score + 11;
    score = score - 18;
    console.log(score);
15. 15.⚡ What does this code show?
    let name = "Riya";
    console.log("Welcome, " + name + "!"); (a) Riya (b) name (c) Welcome, name! (d) Welcome, Riya!
16. 16.⚡ What number does this code print?
    let apples = 27;
    apples = apples + 11;
    apples = apples - 2;
    console.log(apples);
17. 17.⚡ What does this code show?
    let name = "Meera";
    console.log("Well done, " + name + "!"); (a) Well done, name! (b) Well done, Meera! (c) Meera (d) name
18. 18.⚡ What number does this code print?
    let a = 20;
    let b = 21;
    console.log(a + b);
19. 19.⚡ Which JavaScript word repeats code? (a) let (b) console.log() (c) if (d) for
20. 20.⚡ Which JavaScript word writes in the console? (a) if (b) let (c) console.log() (d) for
21. 21.⚡ What number does this code print?
    let a = 60;
    let b = 15;
    console.log(a + b);
22. 22.⚡ What number does this code print?
    let a = 6;
    let b = 8;
    console.log(a * b);
23. 23.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 8;
    console.log(x + y); (a) 10 (b) Error (c) 28
24. 24.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 6;
    console.log(x + y); (a) Error (b) 13 (c) 76
25. 25.⚡ What number does this code print?
    let a = 58;
    let b = 2;
    console.log(a + b);
26. 26.⚡ What does this code show?
    let name = "Aman";
    alert("Well done, " + name + "!"); (a) Well done, name! (b) Well done, Aman! (c) name (d) Aman
27. 27.⚡ What does JavaScript add to a web page? (a) the domain name (b) the page title (c) only colours (d) actions and changes
28. 28.⚡ What does alert() show? (a) a pop-up box (b) a picture (c) a table (d) a new tab
29. 29.⚡ What number does this code print?
    let score = 16;
    score = score + 3;
    score = score - 14;
    console.log(score);
30. 30.⚡ What does this code show?
    let name = "Aman";
    console.log("Hello, " + name + "!"); (a) Hello, Aman! (b) name (c) Aman (d) Hello, name!
31. 31.⚡ What number does this code print?
    let books = 14;
    books = books + 14;
    books = books - 5;
    console.log(books);
32. 32.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <script> (c) <code> (d) <js>
33. 33.⚡ What number does this code print?
    let a = 3;
    let b = 2;
    console.log(a * b);
34. 34.⚡ What number does this code print?
    let a = 17;
    let b = 11;
    console.log(a + b);
35. 35.⚡ What number does this code print?
    let marks = 24;
    marks = marks + 4;
    marks = marks - 5;
    console.log(marks);
36. 36.⚡ What number does this code print?
    let a = 11;
    let b = 3;
    console.log(a * b);
37. 37.⚡ What number does this code print?
    let score = 5;
    score = score + 7;
    score = score - 12;
    console.log(score);
38. 38.⚡ What number does this code print?
    let a = 46;
    let b = 17;
    console.log(a - b);
39. 39.⚡ What number does this code print?
    let a = 38;
    let b = 30;
    console.log(a - b);
40. 40.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 4;
    console.log(x + y); (a) Error (b) 34 (c) 7

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