JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 135 · 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) alert() (b) for (c) if (d) console.log()
2. 2.⚡ What does this code print? (Look at the quotes!)
   let x = "5";
   let y = 1;
   console.log(x + y); (a) 6 (b) 51 (c) Error
3. 3.⚡ Which word makes a new variable? (a) put (b) give (c) let (d) make
4. 4.⚡ What number does this code print?
   let score = 6;
   score = score + 10;
   score = score - 14;
   console.log(score);
5. 5.⚡ What number does this code print?
   let coins = 20;
   coins = coins + 16;
   coins = coins - 11;
   console.log(coins);
6. 6.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .html (c) .jpg (d) .js
7. 7.⚡ What number does this code print?
   let coins = 19;
   coins = coins + 7;
   coins = coins - 21;
   console.log(coins);
8. 8.⚡ What number does this code print?
   let books = 19;
   books = books + 20;
   books = books - 2;
   console.log(books);
9. 9.⚡ What number does this code print?
   let a = 30;
   let b = 10;
   console.log(a + b);
10. 10.⚡ What number does this code print?
    let a = 24;
    let b = 20;
    console.log(a - b);
11. 11.⚡ Which JavaScript word writes in the console? (a) for (b) alert() (c) let (d) console.log()
12. 12.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 5;
    console.log(x + y); (a) 75 (b) Error (c) 12
13. 13.⚡ What number does this code print?
    let apples = 22;
    apples = apples + 15;
    apples = apples - 4;
    console.log(apples);
14. 14.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 3;
    console.log(x + y); (a) 23 (b) Error (c) 5
15. 15.⚡ Which JavaScript word repeats code? (a) if (b) console.log() (c) let (d) for
16. 16.⚡ What number does this code print?
    let marks = 27;
    marks = marks + 18;
    marks = marks - 26;
    console.log(marks);
17. 17.⚡ What does alert() show? (a) a new tab (b) a pop-up box (c) a table (d) a picture
18. 18.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 4;
    console.log(x + y); (a) Error (b) 44 (c) 8
19. 19.⚡ What number does this code print?
    let a = 11;
    let b = 10;
    console.log(a * b);
20. 20.⚡ What number does this code print?
    let a = 12;
    let b = 14;
    console.log(a + b);
21. 21.⚡ What number does this code print?
    let score = 20;
    score = score + 15;
    score = score - 10;
    console.log(score);
22. 22.⚡ What does this code show?
    let name = "Zoya";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) name (c) Zoya (d) Welcome, Zoya!
23. 23.⚡ What number does this code print?
    let a = 33;
    let b = 25;
    console.log(a - b);
24. 24.⚡ What does JavaScript add to a web page? (a) actions and changes (b) the page title (c) only colours (d) the domain name
25. 25.⚡ What number does this code print?
    let a = 9;
    let b = 11;
    console.log(a + b);
26. 26.⚡ What does this code show?
    let name = "Kabir";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Kabir (d) Hello, Kabir!
27. 27.⚡ What number does this code print?
    let a = 11;
    let b = 19;
    console.log(a + b);
28. 28.⚡ What number does this code print?
    let apples = 5;
    apples = apples + 14;
    apples = apples - 12;
    console.log(apples);
29. 29.⚡ Where does console.log() show its output? (a) in the address bar (b) on the title bar (c) on the printer (d) in the console
30. 30.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <code> (c) <script> (d) <js>
31. 31.⚡ What does this code show?
    let name = "Zoya";
    console.log("Well done, " + name + "!"); (a) Zoya (b) Well done, Zoya! (c) name (d) Well done, name!
32. 32.⚡ What number does this code print?
    let a = 51;
    let b = 15;
    console.log(a + b);
33. 33.⚡ Which JavaScript word makes a new variable? (a) let (b) alert() (c) for (d) if
34. 34.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 7;
    console.log(x + y); (a) Error (b) 77 (c) 14
35. 35.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 1;
    console.log(x + y); (a) 71 (b) Error (c) 8
36. 36.⚡ What does this code show?
    let name = "Aman";
    console.log("Well done, " + name + "!"); (a) Aman (b) Well done, Aman! (c) name (d) Well done, name!
37. 37.⚡ What number does this code print?
    let a = 53;
    let b = 9;
    console.log(a - b);
38. 38.⚡ What number does this code print?
    let score = 17;
    score = score + 16;
    score = score - 31;
    console.log(score);
39. 39.⚡ What number does this code print?
    let books = 13;
    books = books + 4;
    books = books - 1;
    console.log(books);
40. 40.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) for (c) let (d) if

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