JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 781 · 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 = 52;
   let b = 23;
   console.log(a - b);
2. 2.⚡ What number does this code print?
   let a = 10;
   let b = 9;
   console.log(a * b);
3. 3.⚡ What does alert() show? (a) a table (b) a picture (c) a pop-up box (d) a new tab
4. 4.⚡ What does this code print? (Look at the quotes!)
   let x = "3";
   let y = 6;
   console.log(x + y); (a) Error (b) 36 (c) 9
5. 5.⚡ What number does this code print?
   let runs = 10;
   runs = runs + 19;
   runs = runs - 5;
   console.log(runs);
6. 6.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <script> (c) <js> (d) <code>
7. 7.⚡ Which JavaScript word makes a new variable? (a) alert() (b) let (c) if (d) for
8. 8.⚡ What number does this code print?
   let apples = 5;
   apples = apples + 10;
   apples = apples - 11;
   console.log(apples);
9. 9.⚡ What does this code print? (Look at the quotes!)
   let x = "8";
   let y = 4;
   console.log(x + y); (a) 12 (b) Error (c) 84
10. 10.⚡ What does this code show?
    let name = "Meera";
    console.log("Hello, " + name + "!"); (a) Hello, Meera! (b) Meera (c) name (d) Hello, name!
11. 11.⚡ What number does this code print?
    let books = 16;
    books = books + 5;
    books = books - 1;
    console.log(books);
12. 12.⚡ What number does this code print?
    let apples = 19;
    apples = apples + 11;
    apples = apples - 18;
    console.log(apples);
13. 13.⚡ Which JavaScript word repeats code? (a) for (b) if (c) let (d) console.log()
14. 14.⚡ What does JavaScript add to a web page? (a) only colours (b) the page title (c) actions and changes (d) the domain name
15. 15.⚡ What number does this code print?
    let coins = 23;
    coins = coins + 18;
    coins = coins - 7;
    console.log(coins);
16. 16.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 4;
    console.log(x + y); (a) 54 (b) Error (c) 9
17. 17.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 8;
    console.log(x + y); (a) 88 (b) 16 (c) Error
18. 18.⚡ What does this code show?
    let name = "Riya";
    alert("Hi, " + name + "!"); (a) Hi, Riya! (b) Hi, name! (c) name (d) Riya
19. 19.⚡ 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
20. 20.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 3;
    console.log(x + y); (a) 10 (b) Error (c) 73
21. 21.⚡ What does this code show?
    let name = "Arjun";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) Hello, Arjun! (c) Arjun (d) name
22. 22.⚡ Which JavaScript word writes in the console? (a) let (b) if (c) console.log() (d) for
23. 23.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 4;
    console.log(x + y); (a) Error (b) 24 (c) 6
24. 24.⚡ Which JavaScript word shows a pop-up box? (a) for (b) console.log() (c) if (d) alert()
25. 25.⚡ What number does this code print?
    let books = 5;
    books = books + 16;
    books = books - 4;
    console.log(books);
26. 26.⚡ What does this code show?
    let name = "Meera";
    alert("Hi, " + name + "!"); (a) Hi, Meera! (b) Hi, name! (c) name (d) Meera
27. 27.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 4;
    console.log(x + y); (a) Error (b) 64 (c) 10
28. 28.⚡ Which JavaScript word runs code when true? (a) for (b) if (c) alert() (d) let
29. 29.⚡ What does this code show?
    let name = "Meera";
    alert("Well done, " + name + "!"); (a) Meera (b) name (c) Well done, name! (d) Well done, Meera!
30. 30.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 9;
    console.log(x + y); (a) 19 (b) 10 (c) Error
31. 31.⚡ What number does this code print?
    let apples = 12;
    apples = apples + 15;
    apples = apples - 10;
    console.log(apples);
32. 32.⚡ What number does this code print?
    let a = 10;
    let b = 7;
    console.log(a * b);
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 3;
    console.log(x + y); (a) Error (b) 43 (c) 7
34. 34.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 8;
    console.log(x + y); (a) Error (b) 12 (c) 48
35. 35.⚡ What number does this code print?
    let a = 45;
    let b = 16;
    console.log(a + b);
36. 36.⚡ What number does this code print?
    let apples = 8;
    apples = apples + 6;
    apples = apples - 9;
    console.log(apples);
37. 37.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 5;
    console.log(x + y); (a) Error (b) 85 (c) 13
38. 38.⚡ What does this code show?
    let name = "Aman";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) Welcome, Aman! (c) Aman (d) name
39. 39.⚡ What number does this code print?
    let runs = 17;
    runs = runs + 4;
    runs = runs - 16;
    console.log(runs);
40. 40.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 9;
    console.log(x + y); (a) 16 (b) Error (c) 79

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