JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 200 · 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) the page title (b) the domain name (c) only colours (d) actions and changes
2. 2.⚡ What does this code show?
   let name = "Meera";
   alert("Hello, " + name + "!"); (a) name (b) Hello, Meera! (c) Hello, name! (d) Meera
3. 3.⚡ What number does this code print?
   let a = 16;
   let b = 25;
   console.log(a + b);
4. 4.⚡ What number does this code print?
   let a = 2;
   let b = 9;
   console.log(a * b);
5. 5.⚡ 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
6. 6.⚡ What number does this code print?
   let score = 14;
   score = score + 2;
   score = score - 4;
   console.log(score);
7. 7.⚡ Which JavaScript word makes a new variable? (a) for (b) alert() (c) console.log() (d) let
8. 8.⚡ Which JavaScript word shows a pop-up box? (a) if (b) alert() (c) for (d) let
9. 9.⚡ What number does this code print?
   let apples = 28;
   apples = apples + 8;
   apples = apples - 28;
   console.log(apples);
10. 10.⚡ Which JavaScript word runs code when true? (a) let (b) if (c) alert() (d) console.log()
11. 11.⚡ What does this code show?
    let name = "Arjun";
    alert("Hi, " + name + "!"); (a) name (b) Hi, Arjun! (c) Arjun (d) Hi, name!
12. 12.⚡ Where does console.log() show its output? (a) on the printer (b) in the console (c) in the address bar (d) on the title bar
13. 13.⚡ What number does this code print?
    let a = 4;
    let b = 12;
    console.log(a * b);
14. 14.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 5;
    console.log(x + y); (a) 8 (b) 35 (c) Error
15. 15.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 2;
    console.log(x + y); (a) 5 (b) 32 (c) Error
16. 16.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 1;
    console.log(x + y); (a) 81 (b) 9 (c) Error
17. 17.⚡ What does this code show?
    let name = "Aman";
    alert("Well done, " + name + "!"); (a) Aman (b) Well done, Aman! (c) Well done, name! (d) name
18. 18.⚡ What does this code show?
    let name = "Aman";
    console.log("Hello, " + name + "!"); (a) name (b) Hello, Aman! (c) Hello, name! (d) Aman
19. 19.⚡ What number does this code print?
    let runs = 11;
    runs = runs + 10;
    runs = runs - 16;
    console.log(runs);
20. 20.⚡ What does this code show?
    let name = "Kabir";
    console.log("Well done, " + name + "!"); (a) name (b) Well done, Kabir! (c) Well done, name! (d) Kabir
21. 21.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <script> (c) <js> (d) <code>
22. 22.⚡ What does this code show?
    let name = "Zoya";
    console.log("Hi, " + name + "!"); (a) name (b) Hi, Zoya! (c) Zoya (d) Hi, name!
23. 23.⚡ What number does this code print?
    let a = 42;
    let b = 30;
    console.log(a + b);
24. 24.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 5;
    console.log(x + y); (a) Error (b) 55 (c) 10
25. 25.⚡ What number does this code print?
    let score = 25;
    score = score + 8;
    score = score - 31;
    console.log(score);
26. 26.⚡ What number does this code print?
    let a = 5;
    let b = 2;
    console.log(a * b);
27. 27.⚡ What number does this code print?
    let a = 39;
    let b = 16;
    console.log(a + b);
28. 28.⚡ What number does this code print?
    let a = 32;
    let b = 8;
    console.log(a - b);
29. 29.⚡ What number does this code print?
    let a = 25;
    let b = 18;
    console.log(a - b);
30. 30.⚡ What number does this code print?
    let a = 18;
    let b = 8;
    console.log(a - b);
31. 31.⚡ What number does this code print?
    let coins = 16;
    coins = coins + 2;
    coins = coins - 8;
    console.log(coins);
32. 32.⚡ What does this code show?
    let name = "Zoya";
    console.log("Well done, " + name + "!"); (a) Zoya (b) Well done, name! (c) name (d) Well done, Zoya!
33. 33.⚡ What does this code show?
    let name = "Kabir";
    alert("Hi, " + name + "!"); (a) name (b) Hi, name! (c) Hi, Kabir! (d) Kabir
34. 34.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 1;
    console.log(x + y); (a) 8 (b) 71 (c) Error
35. 35.⚡ Which JavaScript word repeats code? (a) alert() (b) let (c) if (d) for
36. 36.⚡ 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
37. 37.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .html (c) .jpg (d) .js
38. 38.⚡ What does this code show?
    let name = "Arjun";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) Arjun (c) Welcome, Arjun! (d) name
39. 39.⚡ What number does this code print?
    let a = 8;
    let b = 9;
    console.log(a * b);
40. 40.⚡ What does this code show?
    let name = "Riya";
    console.log("Hi, " + name + "!"); (a) name (b) Hi, name! (c) Hi, Riya! (d) Riya

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