JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 838 · 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 = 25;
   let b = 10;
   console.log(a - b);
2. 2.⚡ Which JavaScript word makes a new variable? (a) console.log() (b) alert() (c) if (d) let
3. 3.⚡ What number does this code print?
   let apples = 24;
   apples = apples + 10;
   apples = apples - 33;
   console.log(apples);
4. 4.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .css (c) .jpg (d) .js
5. 5.⚡ Which JavaScript word runs code when true? (a) alert() (b) console.log() (c) for (d) if
6. 6.⚡ Which JavaScript word shows a pop-up box? (a) if (b) for (c) console.log() (d) alert()
7. 7.⚡ What number does this code print?
   let a = 12;
   let b = 9;
   console.log(a - b);
8. 8.⚡ What does alert() show? (a) a new tab (b) a pop-up box (c) a table (d) a picture
9. 9.⚡ What number does this code print?
   let a = 5;
   let b = 20;
   console.log(a + b);
10. 10.⚡ What does this code show?
    let name = "Riya";
    console.log("Well done, " + name + "!"); (a) Riya (b) Well done, name! (c) Well done, Riya! (d) name
11. 11.⚡ Which JavaScript word writes in the console? (a) if (b) console.log() (c) for (d) let
12. 12.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 3;
    console.log(x + y); (a) 4 (b) 13 (c) Error
13. 13.⚡ What does this code show?
    let name = "Riya";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Hello, Riya! (d) Riya
14. 14.⚡ What number does this code print?
    let coins = 7;
    coins = coins + 5;
    coins = coins - 3;
    console.log(coins);
15. 15.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 9;
    console.log(x + y); (a) 13 (b) 49 (c) Error
16. 16.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 7;
    console.log(x + y); (a) 37 (b) Error (c) 10
17. 17.⚡ What does this code show?
    let name = "Meera";
    console.log("Welcome, " + name + "!"); (a) name (b) Meera (c) Welcome, name! (d) Welcome, Meera!
18. 18.⚡ Where does console.log() show its output? (a) on the title bar (b) on the printer (c) in the console (d) in the address bar
19. 19.⚡ What number does this code print?
    let books = 27;
    books = books + 13;
    books = books - 13;
    console.log(books);
20. 20.⚡ What does this code show?
    let name = "Riya";
    alert("Hi, " + name + "!"); (a) Hi, Riya! (b) Hi, name! (c) Riya (d) name
21. 21.⚡ What number does this code print?
    let a = 11;
    let b = 8;
    console.log(a - b);
22. 22.⚡ What does this code show?
    let name = "Meera";
    console.log("Hi, " + name + "!"); (a) Hi, name! (b) name (c) Meera (d) Hi, Meera!
23. 23.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 2;
    console.log(x + y); (a) Error (b) 11 (c) 92
24. 24.⚡ What number does this code print?
    let a = 8;
    let b = 31;
    console.log(a + b);
25. 25.⚡ What number does this code print?
    let a = 46;
    let b = 28;
    console.log(a + b);
26. 26.⚡ What does this code show?
    let name = "Zoya";
    console.log("Hi, " + name + "!"); (a) Hi, name! (b) Zoya (c) name (d) Hi, Zoya!
27. 27.⚡ What number does this code print?
    let a = 6;
    let b = 10;
    console.log(a * b);
28. 28.⚡ What does this code show?
    let name = "Arjun";
    alert("Hello, " + name + "!"); (a) name (b) Hello, name! (c) Hello, Arjun! (d) Arjun
29. 29.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <code> (c) <script> (d) <js>
30. 30.⚡ What number does this code print?
    let a = 26;
    let b = 6;
    console.log(a + b);
31. 31.⚡ 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
32. 32.⚡ Which JavaScript word repeats code? (a) alert() (b) console.log() (c) for (d) if
33. 33.⚡ What number does this code print?
    let a = 11;
    let b = 9;
    console.log(a - b);
34. 34.⚡ What does this code show?
    let name = "Riya";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) Riya (c) name (d) Hello, Riya!
35. 35.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 1;
    console.log(x + y); (a) Error (b) 11 (c) 2
36. 36.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 8;
    console.log(x + y); (a) 38 (b) 11 (c) Error
37. 37.⚡ What number does this code print?
    let coins = 17;
    coins = coins + 7;
    coins = coins - 9;
    console.log(coins);
38. 38.⚡ What number does this code print?
    let a = 24;
    let b = 6;
    console.log(a - b);
39. 39.⚡ What number does this code print?
    let a = 39;
    let b = 10;
    console.log(a - b);
40. 40.⚡ What number does this code print?
    let a = 39;
    let b = 17;
    console.log(a - b);

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