JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 921 · 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 marks = 21;
   marks = marks + 20;
   marks = marks - 3;
   console.log(marks);
2. 2.⚡ What number does this code print?
   let a = 34;
   let b = 22;
   console.log(a + b);
3. 3.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .jpg (c) .html (d) .js
4. 4.⚡ Where does console.log() show its output? (a) in the address bar (b) on the title bar (c) in the console (d) on the printer
5. 5.⚡ What does this code show?
   let name = "Aman";
   alert("Hi, " + name + "!"); (a) name (b) Hi, Aman! (c) Hi, name! (d) Aman
6. 6.⚡ What number does this code print?
   let a = 48;
   let b = 29;
   console.log(a - b);
7. 7.⚡ What does this code show?
   let name = "Riya";
   alert("Welcome, " + name + "!"); (a) Welcome, name! (b) Welcome, Riya! (c) name (d) Riya
8. 8.⚡ Which JavaScript word runs code when true? (a) if (b) console.log() (c) alert() (d) let
9. 9.⚡ What does this code show?
   let name = "Kabir";
   console.log("Well done, " + name + "!"); (a) name (b) Well done, Kabir! (c) Well done, name! (d) Kabir
10. 10.⚡ What does JavaScript add to a web page? (a) the page title (b) actions and changes (c) the domain name (d) only colours
11. 11.⚡ What does this code show?
    let name = "Riya";
    alert("Hi, " + name + "!"); (a) Hi, name! (b) Riya (c) Hi, Riya! (d) name
12. 12.⚡ What does alert() show? (a) a table (b) a new tab (c) a pop-up box (d) a picture
13. 13.⚡ What does this code show?
    let name = "Meera";
    alert("Hi, " + name + "!"); (a) Meera (b) name (c) Hi, name! (d) Hi, Meera!
14. 14.⚡ What does this code show?
    let name = "Kabir";
    alert("Well done, " + name + "!"); (a) Kabir (b) Well done, name! (c) name (d) Well done, Kabir!
15. 15.⚡ What does this code show?
    let name = "Zoya";
    alert("Hi, " + name + "!"); (a) name (b) Hi, name! (c) Zoya (d) Hi, Zoya!
16. 16.⚡ Which JavaScript word makes a new variable? (a) if (b) for (c) let (d) console.log()
17. 17.⚡ What does this code show?
    let name = "Meera";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Hello, Meera! (d) Meera
18. 18.⚡ Which JavaScript word shows a pop-up box? (a) for (b) let (c) if (d) alert()
19. 19.⚡ Which word makes a new variable? (a) let (b) put (c) make (d) give
20. 20.⚡ Which JavaScript word repeats code? (a) let (b) for (c) console.log() (d) alert()
21. 21.⚡ What number does this code print?
    let books = 11;
    books = books + 19;
    books = books - 4;
    console.log(books);
22. 22.⚡ What number does this code print?
    let score = 25;
    score = score + 19;
    score = score - 32;
    console.log(score);
23. 23.⚡ What number does this code print?
    let marks = 21;
    marks = marks + 8;
    marks = marks - 6;
    console.log(marks);
24. 24.⚡ Which JavaScript word writes in the console? (a) let (b) if (c) console.log() (d) for
25. 25.⚡ What number does this code print?
    let a = 41;
    let b = 8;
    console.log(a + b);
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 1;
    console.log(x + y); (a) 11 (b) 2 (c) Error
27. 27.⚡ What number does this code print?
    let marks = 19;
    marks = marks + 12;
    marks = marks - 7;
    console.log(marks);
28. 28.⚡ What number does this code print?
    let a = 38;
    let b = 20;
    console.log(a + b);
29. 29.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <style> (c) <js> (d) <script>
30. 30.⚡ What number does this code print?
    let a = 43;
    let b = 3;
    console.log(a + b);
31. 31.⚡ 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
32. 32.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 3;
    console.log(x + y); (a) 43 (b) Error (c) 7
33. 33.⚡ What number does this code print?
    let a = 37;
    let b = 22;
    console.log(a - b);
34. 34.⚡ What does this code show?
    let name = "Aman";
    alert("Welcome, " + name + "!"); (a) Welcome, Aman! (b) Aman (c) Welcome, name! (d) name
35. 35.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 3;
    console.log(x + y); (a) 9 (b) Error (c) 63
36. 36.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 7;
    console.log(x + y); (a) 77 (b) 14 (c) Error
37. 37.⚡ What does this code show?
    let name = "Meera";
    alert("Well done, " + name + "!"); (a) Well done, name! (b) Meera (c) name (d) Well done, Meera!
38. 38.⚡ What number does this code print?
    let a = 55;
    let b = 32;
    console.log(a + b);
39. 39.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 2;
    console.log(x + y); (a) Error (b) 32 (c) 5
40. 40.⚡ What number does this code print?
    let marks = 29;
    marks = marks + 4;
    marks = marks - 4;
    console.log(marks);

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