JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 784 · 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 = 27;
   let b = 13;
   console.log(a + b);
2. 2.⚡ Which word makes a new variable? (a) make (b) put (c) let (d) give
3. 3.⚡ What number does this code print?
   let score = 16;
   score = score + 16;
   score = score - 14;
   console.log(score);
4. 4.⚡ Which JavaScript word writes in the console? (a) if (b) alert() (c) console.log() (d) let
5. 5.⚡ What does alert() show? (a) a table (b) a new tab (c) a picture (d) a pop-up box
6. 6.⚡ What does this code print? (Look at the quotes!)
   let x = "8";
   let y = 3;
   console.log(x + y); (a) 83 (b) Error (c) 11
7. 7.⚡ What number does this code print?
   let apples = 30;
   apples = apples + 7;
   apples = apples - 9;
   console.log(apples);
8. 8.⚡ What number does this code print?
   let a = 7;
   let b = 6;
   console.log(a * b);
9. 9.⚡ 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
10. 10.⚡ What number does this code print?
    let a = 9;
    let b = 4;
    console.log(a * b);
11. 11.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .css (c) .html (d) .jpg
12. 12.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hi, " + name + "!"); (a) name (b) Hi, name! (c) Hi, Kabir! (d) Kabir
13. 13.⚡ Which JavaScript word runs code when true? (a) alert() (b) console.log() (c) if (d) for
14. 14.⚡ Which JavaScript word shows a pop-up box? (a) for (b) console.log() (c) let (d) alert()
15. 15.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 2;
    console.log(x + y); (a) 10 (b) Error (c) 82
16. 16.⚡ Which JavaScript word repeats code? (a) console.log() (b) if (c) for (d) let
17. 17.⚡ What number does this code print?
    let score = 10;
    score = score + 20;
    score = score - 10;
    console.log(score);
18. 18.⚡ What does JavaScript add to a web page? (a) actions and changes (b) the page title (c) only colours (d) the domain name
19. 19.⚡ What does this code show?
    let name = "Meera";
    console.log("Hi, " + name + "!"); (a) name (b) Hi, name! (c) Meera (d) Hi, Meera!
20. 20.⚡ What does this code show?
    let name = "Zoya";
    alert("Hi, " + name + "!"); (a) name (b) Hi, Zoya! (c) Zoya (d) Hi, name!
21. 21.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 1;
    console.log(x + y); (a) 6 (b) Error (c) 51
22. 22.⚡ What number does this code print?
    let marks = 29;
    marks = marks + 5;
    marks = marks - 24;
    console.log(marks);
23. 23.⚡ Which tag holds JavaScript in a page? (a) <script> (b) <js> (c) <code> (d) <style>
24. 24.⚡ What number does this code print?
    let a = 17;
    let b = 32;
    console.log(a + b);
25. 25.⚡ What does this code show?
    let name = "Meera";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) name (c) Welcome, Meera! (d) Meera
26. 26.⚡ What number does this code print?
    let books = 11;
    books = books + 18;
    books = books - 11;
    console.log(books);
27. 27.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 1;
    console.log(x + y); (a) Error (b) 7 (c) 61
28. 28.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 8;
    console.log(x + y); (a) Error (b) 16 (c) 88
29. 29.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 4;
    console.log(x + y); (a) Error (b) 94 (c) 13
30. 30.⚡ What does this code show?
    let name = "Arjun";
    alert("Well done, " + name + "!"); (a) name (b) Well done, Arjun! (c) Well done, name! (d) Arjun
31. 31.⚡ What number does this code print?
    let a = 40;
    let b = 12;
    console.log(a - b);
32. 32.⚡ What number does this code print?
    let runs = 6;
    runs = runs + 7;
    runs = runs - 2;
    console.log(runs);
33. 33.⚡ What number does this code print?
    let a = 47;
    let b = 2;
    console.log(a - b);
34. 34.⚡ Which JavaScript word makes a new variable? (a) console.log() (b) alert() (c) let (d) if
35. 35.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 5;
    console.log(x + y); (a) 12 (b) Error (c) 75
36. 36.⚡ What number does this code print?
    let books = 19;
    books = books + 2;
    books = books - 7;
    console.log(books);
37. 37.⚡ What number does this code print?
    let a = 9;
    let b = 12;
    console.log(a * b);
38. 38.⚡ What does this code show?
    let name = "Zoya";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) name (c) Welcome, Zoya! (d) Zoya
39. 39.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Kabir (d) Hello, Kabir!
40. 40.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 9;
    console.log(x + y); (a) 10 (b) Error (c) 19

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