JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 830 · 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 JavaScript add to a web page? (a) actions and changes (b) only colours (c) the page title (d) the domain name
2. 2.⚡ Where does console.log() show its output? (a) in the console (b) on the printer (c) in the address bar (d) on the title bar
3. 3.⚡ What number does this code print?
   let apples = 17;
   apples = apples + 3;
   apples = apples - 2;
   console.log(apples);
4. 4.⚡ Which word makes a new variable? (a) let (b) put (c) give (d) make
5. 5.⚡ What does alert() show? (a) a pop-up box (b) a picture (c) a new tab (d) a table
6. 6.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .html (c) .js (d) .jpg
7. 7.⚡ Which JavaScript word shows a pop-up box? (a) for (b) if (c) alert() (d) console.log()
8. 8.⚡ Which tag holds JavaScript in a page? (a) <script> (b) <code> (c) <js> (d) <style>
9. 9.⚡ What does this code print? (Look at the quotes!)
   let x = "5";
   let y = 8;
   console.log(x + y); (a) 58 (b) Error (c) 13
10. 10.⚡ Which JavaScript word writes in the console? (a) console.log() (b) if (c) alert() (d) let
11. 11.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 1;
    console.log(x + y); (a) 41 (b) 5 (c) Error
12. 12.⚡ What number does this code print?
    let a = 2;
    let b = 3;
    console.log(a * b);
13. 13.⚡ What does this code show?
    let name = "Aman";
    console.log("Hello, " + name + "!"); (a) name (b) Aman (c) Hello, Aman! (d) Hello, name!
14. 14.⚡ Which JavaScript word makes a new variable? (a) alert() (b) console.log() (c) let (d) for
15. 15.⚡ Which JavaScript word runs code when true? (a) alert() (b) console.log() (c) for (d) if
16. 16.⚡ What does this code show?
    let name = "Riya";
    console.log("Hello, " + name + "!"); (a) Riya (b) name (c) Hello, name! (d) Hello, Riya!
17. 17.⚡ What number does this code print?
    let apples = 15;
    apples = apples + 7;
    apples = apples - 16;
    console.log(apples);
18. 18.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 3;
    console.log(x + y); (a) 6 (b) Error (c) 33
19. 19.⚡ Which JavaScript word repeats code? (a) for (b) let (c) if (d) console.log()
20. 20.⚡ What does this code show?
    let name = "Aman";
    console.log("Hi, " + name + "!"); (a) name (b) Hi, name! (c) Hi, Aman! (d) Aman
21. 21.⚡ What number does this code print?
    let a = 15;
    let b = 12;
    console.log(a - b);
22. 22.⚡ What number does this code print?
    let coins = 6;
    coins = coins + 18;
    coins = coins - 9;
    console.log(coins);
23. 23.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 9;
    console.log(x + y); (a) 15 (b) Error (c) 69
24. 24.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 5;
    console.log(x + y); (a) 7 (b) Error (c) 25
25. 25.⚡ What number does this code print?
    let a = 26;
    let b = 8;
    console.log(a - b);
26. 26.⚡ What number does this code print?
    let a = 10;
    let b = 6;
    console.log(a * b);
27. 27.⚡ What number does this code print?
    let runs = 23;
    runs = runs + 5;
    runs = runs - 2;
    console.log(runs);
28. 28.⚡ What number does this code print?
    let a = 53;
    let b = 27;
    console.log(a - b);
29. 29.⚡ What number does this code print?
    let marks = 29;
    marks = marks + 17;
    marks = marks - 22;
    console.log(marks);
30. 30.⚡ 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
31. 31.⚡ What number does this code print?
    let a = 54;
    let b = 8;
    console.log(a + b);
32. 32.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 2;
    console.log(x + y); (a) 32 (b) Error (c) 5
33. 33.⚡ What does this code show?
    let name = "Arjun";
    alert("Hello, " + name + "!"); (a) Arjun (b) Hello, name! (c) name (d) Hello, Arjun!
34. 34.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 3;
    console.log(x + y); (a) 73 (b) 10 (c) Error
35. 35.⚡ What number does this code print?
    let a = 9;
    let b = 1;
    console.log(a + b);
36. 36.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 9;
    console.log(x + y); (a) 19 (b) Error (c) 10
37. 37.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hello, " + name + "!"); (a) Kabir (b) Hello, name! (c) name (d) Hello, Kabir!
38. 38.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 3;
    console.log(x + y); (a) Error (b) 63 (c) 9
39. 39.⚡ What number does this code print?
    let a = 5;
    let b = 2;
    console.log(a * b);
40. 40.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hi, " + name + "!"); (a) Kabir (b) name (c) Hi, Kabir! (d) Hi, name!

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