JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 901 · 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 makes a new variable? (a) console.log() (b) let (c) for (d) if
2. 2.⚡ What number does this code print?
   let a = 14;
   let b = 32;
   console.log(a + b);
3. 3.⚡ What does this code print? (Look at the quotes!)
   let x = "9";
   let y = 5;
   console.log(x + y); (a) Error (b) 14 (c) 95
4. 4.⚡ What number does this code print?
   let a = 48;
   let b = 21;
   console.log(a + b);
5. 5.⚡ What does this code print? (Look at the quotes!)
   let x = "4";
   let y = 2;
   console.log(x + y); (a) Error (b) 6 (c) 42
6. 6.⚡ What number does this code print?
   let a = 4;
   let b = 9;
   console.log(a * b);
7. 7.⚡ What does this code show?
   let name = "Meera";
   console.log("Hello, " + name + "!"); (a) Hello, Meera! (b) Hello, name! (c) name (d) Meera
8. 8.⚡ Which JavaScript word repeats code? (a) alert() (b) for (c) let (d) console.log()
9. 9.⚡ What number does this code print?
   let apples = 25;
   apples = apples + 2;
   apples = apples - 13;
   console.log(apples);
10. 10.⚡ Which JavaScript word shows a pop-up box? (a) let (b) for (c) console.log() (d) alert()
11. 11.⚡ Which JavaScript word writes in the console? (a) for (b) if (c) let (d) console.log()
12. 12.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .jpg (c) .js (d) .html
13. 13.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 6;
    console.log(x + y); (a) Error (b) 9 (c) 36
14. 14.⚡ What number does this code print?
    let a = 25;
    let b = 19;
    console.log(a - b);
15. 15.⚡ What number does this code print?
    let a = 32;
    let b = 7;
    console.log(a - b);
16. 16.⚡ What number does this code print?
    let a = 8;
    let b = 9;
    console.log(a * b);
17. 17.⚡ Where does console.log() show its output? (a) in the console (b) in the address bar (c) on the title bar (d) on the printer
18. 18.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 2;
    console.log(x + y); (a) Error (b) 12 (c) 3
19. 19.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 6;
    console.log(x + y); (a) 11 (b) Error (c) 56
20. 20.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 6;
    console.log(x + y); (a) 66 (b) 12 (c) Error
21. 21.⚡ What does JavaScript add to a web page? (a) only colours (b) the page title (c) actions and changes (d) the domain name
22. 22.⚡ What number does this code print?
    let score = 5;
    score = score + 19;
    score = score - 5;
    console.log(score);
23. 23.⚡ What does this code show?
    let name = "Arjun";
    alert("Welcome, " + name + "!"); (a) name (b) Welcome, name! (c) Arjun (d) Welcome, Arjun!
24. 24.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <js> (c) <script> (d) <style>
25. 25.⚡ What number does this code print?
    let a = 18;
    let b = 11;
    console.log(a - b);
26. 26.⚡ What number does this code print?
    let score = 9;
    score = score + 12;
    score = score - 12;
    console.log(score);
27. 27.⚡ What number does this code print?
    let a = 31;
    let b = 32;
    console.log(a + b);
28. 28.⚡ What number does this code print?
    let books = 26;
    books = books + 14;
    books = books - 4;
    console.log(books);
29. 29.⚡ What number does this code print?
    let a = 24;
    let b = 5;
    console.log(a - b);
30. 30.⚡ Which word makes a new variable? (a) make (b) put (c) give (d) let
31. 31.⚡ What number does this code print?
    let a = 20;
    let b = 23;
    console.log(a + b);
32. 32.⚡ What does this code show?
    let name = "Riya";
    console.log("Welcome, " + name + "!"); (a) Welcome, Riya! (b) Welcome, name! (c) Riya (d) name
33. 33.⚡ What number does this code print?
    let books = 7;
    books = books + 5;
    books = books - 2;
    console.log(books);
34. 34.⚡ What number does this code print?
    let a = 41;
    let b = 31;
    console.log(a - b);
35. 35.⚡ Which JavaScript word runs code when true? (a) for (b) console.log() (c) if (d) let
36. 36.⚡ What number does this code print?
    let apples = 15;
    apples = apples + 11;
    apples = apples - 4;
    console.log(apples);
37. 37.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 3;
    console.log(x + y); (a) Error (b) 5 (c) 23
38. 38.⚡ What number does this code print?
    let a = 11;
    let b = 5;
    console.log(a * b);
39. 39.⚡ What number does this code print?
    let a = 13;
    let b = 23;
    console.log(a + b);
40. 40.⚡ What number does this code print?
    let score = 10;
    score = score + 13;
    score = score - 10;
    console.log(score);

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