JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 903 · 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 = 52;
   let b = 31;
   console.log(a - b);
2. 2.⚡ Which word makes a new variable? (a) make (b) let (c) put (d) give
3. 3.⚡ What does JavaScript add to a web page? (a) only colours (b) the domain name (c) actions and changes (d) the page title
4. 4.⚡ What does alert() show? (a) a pop-up box (b) a new tab (c) a table (d) a picture
5. 5.⚡ What does this code show?
   let name = "Meera";
   alert("Well done, " + name + "!"); (a) Well done, Meera! (b) Well done, name! (c) Meera (d) name
6. 6.⚡ Where does console.log() show its output? (a) in the console (b) on the title bar (c) in the address bar (d) on the printer
7. 7.⚡ What number does this code print?
   let books = 25;
   books = books + 20;
   books = books - 4;
   console.log(books);
8. 8.⚡ What does this code print? (Look at the quotes!)
   let x = "2";
   let y = 6;
   console.log(x + y); (a) Error (b) 8 (c) 26
9. 9.⚡ What number does this code print?
   let books = 22;
   books = books + 7;
   books = books - 8;
   console.log(books);
10. 10.⚡ Which tag holds JavaScript in a page? (a) <js> (b) <code> (c) <script> (d) <style>
11. 11.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 3;
    console.log(x + y); (a) 5 (b) Error (c) 23
12. 12.⚡ What number does this code print?
    let marks = 27;
    marks = marks + 16;
    marks = marks - 25;
    console.log(marks);
13. 13.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 7;
    console.log(x + y); (a) Error (b) 47 (c) 11
14. 14.⚡ Which JavaScript word writes in the console? (a) console.log() (b) let (c) for (d) alert()
15. 15.⚡ What number does this code print?
    let marks = 13;
    marks = marks + 13;
    marks = marks - 14;
    console.log(marks);
16. 16.⚡ What number does this code print?
    let marks = 12;
    marks = marks + 11;
    marks = marks - 5;
    console.log(marks);
17. 17.⚡ What number does this code print?
    let a = 53;
    let b = 25;
    console.log(a - b);
18. 18.⚡ What number does this code print?
    let a = 36;
    let b = 8;
    console.log(a + b);
19. 19.⚡ What does this code show?
    let name = "Arjun";
    console.log("Well done, " + name + "!"); (a) Well done, Arjun! (b) Well done, name! (c) Arjun (d) name
20. 20.⚡ What number does this code print?
    let score = 9;
    score = score + 3;
    score = score - 10;
    console.log(score);
21. 21.⚡ Which JavaScript word runs code when true? (a) alert() (b) if (c) for (d) console.log()
22. 22.⚡ What number does this code print?
    let a = 5;
    let b = 6;
    console.log(a * b);
23. 23.⚡ Which JavaScript word repeats code? (a) alert() (b) let (c) if (d) for
24. 24.⚡ What does this code show?
    let name = "Zoya";
    console.log("Welcome, " + name + "!"); (a) Welcome, Zoya! (b) Zoya (c) Welcome, name! (d) name
25. 25.⚡ What number does this code print?
    let books = 7;
    books = books + 10;
    books = books - 5;
    console.log(books);
26. 26.⚡ What number does this code print?
    let apples = 9;
    apples = apples + 13;
    apples = apples - 6;
    console.log(apples);
27. 27.⚡ What number does this code print?
    let a = 8;
    let b = 6;
    console.log(a + b);
28. 28.⚡ What number does this code print?
    let a = 4;
    let b = 3;
    console.log(a * b);
29. 29.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 4;
    console.log(x + y); (a) 11 (b) 74 (c) Error
30. 30.⚡ What number does this code print?
    let apples = 11;
    apples = apples + 8;
    apples = apples - 15;
    console.log(apples);
31. 31.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) console.log() (c) if (d) let
32. 32.⚡ What number does this code print?
    let runs = 19;
    runs = runs + 18;
    runs = runs - 12;
    console.log(runs);
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 8;
    console.log(x + y); (a) 16 (b) Error (c) 88
34. 34.⚡ What does this code show?
    let name = "Aman";
    alert("Welcome, " + name + "!"); (a) name (b) Welcome, name! (c) Welcome, Aman! (d) Aman
35. 35.⚡ What number does this code print?
    let a = 60;
    let b = 5;
    console.log(a + b);
36. 36.⚡ What number does this code print?
    let score = 29;
    score = score + 4;
    score = score - 29;
    console.log(score);
37. 37.⚡ What does this code show?
    let name = "Meera";
    console.log("Hello, " + name + "!"); (a) Hello, Meera! (b) name (c) Hello, name! (d) Meera
38. 38.⚡ What does this code show?
    let name = "Kabir";
    alert("Hi, " + name + "!"); (a) Hi, name! (b) Kabir (c) Hi, Kabir! (d) name
39. 39.⚡ What number does this code print?
    let score = 27;
    score = score + 15;
    score = score - 23;
    console.log(score);
40. 40.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .jpg (c) .js (d) .html

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