JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 46 · 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 does this code print? (Look at the quotes!)
   let x = "5";
   let y = 7;
   console.log(x + y); (a) 12 (b) 57 (c) Error
2. 2.⚡ A JavaScript file usually ends with which extension? (a) .jpg (b) .css (c) .js (d) .html
3. 3.⚡ Which JavaScript word makes a new variable? (a) for (b) if (c) console.log() (d) let
4. 4.⚡ What number does this code print?
   let books = 29;
   books = books + 16;
   books = books - 16;
   console.log(books);
5. 5.⚡ Which JavaScript word writes in the console? (a) alert() (b) if (c) console.log() (d) for
6. 6.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <js> (c) <code> (d) <script>
7. 7.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) let (c) console.log() (d) if
8. 8.⚡ What does JavaScript add to a web page? (a) the domain name (b) actions and changes (c) only colours (d) the page title
9. 9.⚡ What does this code show?
   let name = "Aman";
   alert("Well done, " + name + "!"); (a) name (b) Well done, Aman! (c) Aman (d) Well done, name!
10. 10.⚡ What does this code show?
    let name = "Riya";
    alert("Hi, " + name + "!"); (a) name (b) Riya (c) Hi, Riya! (d) Hi, name!
11. 11.⚡ What number does this code print?
    let books = 8;
    books = books + 19;
    books = books - 2;
    console.log(books);
12. 12.⚡ What does this code show?
    let name = "Arjun";
    console.log("Hello, " + name + "!"); (a) Hello, Arjun! (b) Arjun (c) name (d) Hello, name!
13. 13.⚡ What number does this code print?
    let a = 2;
    let b = 8;
    console.log(a * b);
14. 14.⚡ What number does this code print?
    let a = 46;
    let b = 23;
    console.log(a + b);
15. 15.⚡ What does this code show?
    let name = "Aman";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) Welcome, Aman! (c) Aman (d) name
16. 16.⚡ Where does console.log() show its output? (a) in the console (b) on the printer (c) on the title bar (d) in the address bar
17. 17.⚡ What number does this code print?
    let runs = 15;
    runs = runs + 8;
    runs = runs - 4;
    console.log(runs);
18. 18.⚡ What number does this code print?
    let marks = 22;
    marks = marks + 10;
    marks = marks - 8;
    console.log(marks);
19. 19.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 2;
    console.log(x + y); (a) Error (b) 92 (c) 11
20. 20.⚡ What number does this code print?
    let books = 19;
    books = books + 11;
    books = books - 1;
    console.log(books);
21. 21.⚡ What number does this code print?
    let a = 18;
    let b = 11;
    console.log(a - b);
22. 22.⚡ What number does this code print?
    let a = 4;
    let b = 8;
    console.log(a * b);
23. 23.⚡ What number does this code print?
    let a = 12;
    let b = 10;
    console.log(a * b);
24. 24.⚡ Which JavaScript word repeats code? (a) let (b) for (c) console.log() (d) alert()
25. 25.⚡ What number does this code print?
    let a = 17;
    let b = 32;
    console.log(a + b);
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 3;
    console.log(x + y); (a) Error (b) 8 (c) 53
27. 27.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 2;
    console.log(x + y); (a) 6 (b) Error (c) 42
28. 28.⚡ What number does this code print?
    let a = 16;
    let b = 13;
    console.log(a - b);
29. 29.⚡ What number does this code print?
    let apples = 8;
    apples = apples + 20;
    apples = apples - 26;
    console.log(apples);
30. 30.⚡ 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
31. 31.⚡ Which JavaScript word runs code when true? (a) if (b) console.log() (c) let (d) alert()
32. 32.⚡ What number does this code print?
    let score = 8;
    score = score + 12;
    score = score - 7;
    console.log(score);
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 9;
    console.log(x + y); (a) 12 (b) 39 (c) Error
34. 34.⚡ Which word makes a new variable? (a) make (b) let (c) give (d) put
35. 35.⚡ What number does this code print?
    let a = 36;
    let b = 18;
    console.log(a - b);
36. 36.⚡ What number does this code print?
    let a = 24;
    let b = 10;
    console.log(a - b);
37. 37.⚡ What number does this code print?
    let a = 21;
    let b = 11;
    console.log(a + b);
38. 38.⚡ What does this code show?
    let name = "Meera";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) Meera (c) name (d) Hello, Meera!
39. 39.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 2;
    console.log(x + y); (a) 52 (b) Error (c) 7
40. 40.⚡ What number does this code print?
    let a = 30;
    let b = 16;
    console.log(a - b);

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