JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 604 · 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 = 29;
   let b = 20;
   console.log(a + b);
2. 2.⚡ Which JavaScript word shows a pop-up box? (a) if (b) alert() (c) for (d) console.log()
3. 3.⚡ What does this code print? (Look at the quotes!)
   let x = "3";
   let y = 9;
   console.log(x + y); (a) 12 (b) Error (c) 39
4. 4.⚡ What number does this code print?
   let a = 32;
   let b = 25;
   console.log(a - b);
5. 5.⚡ What number does this code print?
   let books = 26;
   books = books + 16;
   books = books - 25;
   console.log(books);
6. 6.⚡ What does this code show?
   let name = "Meera";
   alert("Hi, " + name + "!"); (a) Hi, Meera! (b) Meera (c) Hi, name! (d) name
7. 7.⚡ What does this code show?
   let name = "Zoya";
   console.log("Welcome, " + name + "!"); (a) name (b) Welcome, name! (c) Zoya (d) Welcome, Zoya!
8. 8.⚡ What does this code print? (Look at the quotes!)
   let x = "7";
   let y = 4;
   console.log(x + y); (a) Error (b) 74 (c) 11
9. 9.⚡ Which word makes a new variable? (a) give (b) put (c) make (d) let
10. 10.⚡ Which JavaScript word runs code when true? (a) alert() (b) for (c) console.log() (d) if
11. 11.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <script> (c) <js> (d) <style>
12. 12.⚡ What does this code show?
    let name = "Arjun";
    alert("Well done, " + name + "!"); (a) Well done, name! (b) Arjun (c) name (d) Well done, Arjun!
13. 13.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 6;
    console.log(x + y); (a) 10 (b) Error (c) 46
14. 14.⚡ What number does this code print?
    let a = 25;
    let b = 12;
    console.log(a + b);
15. 15.⚡ What number does this code print?
    let score = 7;
    score = score + 9;
    score = score - 2;
    console.log(score);
16. 16.⚡ Which JavaScript word makes a new variable? (a) if (b) let (c) alert() (d) console.log()
17. 17.⚡ What does this code show?
    let name = "Arjun";
    alert("Hello, " + name + "!"); (a) Arjun (b) Hello, Arjun! (c) name (d) Hello, name!
18. 18.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 7;
    console.log(x + y); (a) Error (b) 16 (c) 97
19. 19.⚡ What does this code show?
    let name = "Riya";
    console.log("Welcome, " + name + "!"); (a) name (b) Welcome, name! (c) Riya (d) Welcome, Riya!
20. 20.⚡ What number does this code print?
    let coins = 13;
    coins = coins + 20;
    coins = coins - 9;
    console.log(coins);
21. 21.⚡ What does this code show?
    let name = "Meera";
    alert("Hello, " + name + "!"); (a) name (b) Meera (c) Hello, name! (d) Hello, Meera!
22. 22.⚡ What number does this code print?
    let coins = 5;
    coins = coins + 17;
    coins = coins - 15;
    console.log(coins);
23. 23.⚡ Which JavaScript word repeats code? (a) for (b) console.log() (c) let (d) alert()
24. 24.⚡ What does this code show?
    let name = "Aman";
    alert("Well done, " + name + "!"); (a) Well done, name! (b) Aman (c) name (d) Well done, Aman!
25. 25.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 3;
    console.log(x + y); (a) 11 (b) Error (c) 83
26. 26.⚡ What does this code show?
    let name = "Arjun";
    console.log("Well done, " + name + "!"); (a) Well done, name! (b) name (c) Well done, Arjun! (d) Arjun
27. 27.⚡ What does this code show?
    let name = "Arjun";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) Arjun (c) Hello, Arjun! (d) name
28. 28.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .html (c) .js (d) .jpg
29. 29.⚡ What does alert() show? (a) a picture (b) a new tab (c) a pop-up box (d) a table
30. 30.⚡ What does this code show?
    let name = "Riya";
    console.log("Hello, " + name + "!"); (a) Hello, Riya! (b) name (c) Hello, name! (d) Riya
31. 31.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 8;
    console.log(x + y); (a) 13 (b) Error (c) 58
32. 32.⚡ What number does this code print?
    let score = 23;
    score = score + 14;
    score = score - 5;
    console.log(score);
33. 33.⚡ What does this code show?
    let name = "Riya";
    console.log("Well done, " + name + "!"); (a) Well done, Riya! (b) Riya (c) name (d) Well done, name!
34. 34.⚡ 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
35. 35.⚡ What number does this code print?
    let a = 50;
    let b = 12;
    console.log(a + b);
36. 36.⚡ What number does this code print?
    let a = 5;
    let b = 12;
    console.log(a * b);
37. 37.⚡ What does this code show?
    let name = "Arjun";
    alert("Hi, " + name + "!"); (a) name (b) Hi, Arjun! (c) Hi, name! (d) Arjun
38. 38.⚡ What number does this code print?
    let coins = 25;
    coins = coins + 5;
    coins = coins - 7;
    console.log(coins);
39. 39.⚡ Where does console.log() show its output? (a) on the title bar (b) in the console (c) on the printer (d) in the address bar
40. 40.⚡ What number does this code print?
    let marks = 24;
    marks = marks + 15;
    marks = marks - 28;
    console.log(marks);

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