JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 944 · 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 = 28;
   console.log(a - b);
2. 2.⚡ Which word makes a new variable? (a) let (b) put (c) give (d) make
3. 3.⚡ What does this code print? (Look at the quotes!)
   let x = "2";
   let y = 3;
   console.log(x + y); (a) Error (b) 5 (c) 23
4. 4.⚡ What number does this code print?
   let a = 43;
   let b = 21;
   console.log(a + b);
5. 5.⚡ Which JavaScript word runs code when true? (a) let (b) alert() (c) if (d) console.log()
6. 6.⚡ What does this code show?
   let name = "Meera";
   alert("Welcome, " + name + "!"); (a) name (b) Welcome, name! (c) Welcome, Meera! (d) Meera
7. 7.⚡ What does this code show?
   let name = "Zoya";
   alert("Well done, " + name + "!"); (a) Zoya (b) Well done, name! (c) Well done, Zoya! (d) name
8. 8.⚡ What does JavaScript add to a web page? (a) the domain name (b) only colours (c) the page title (d) actions and changes
9. 9.⚡ Which JavaScript word writes in the console? (a) console.log() (b) let (c) for (d) alert()
10. 10.⚡ What number does this code print?
    let coins = 26;
    coins = coins + 17;
    coins = coins - 9;
    console.log(coins);
11. 11.⚡ Which JavaScript word shows a pop-up box? (a) for (b) alert() (c) console.log() (d) let
12. 12.⚡ What does this code show?
    let name = "Kabir";
    alert("Hi, " + name + "!"); (a) Kabir (b) name (c) Hi, Kabir! (d) Hi, name!
13. 13.⚡ What number does this code print?
    let a = 16;
    let b = 4;
    console.log(a - b);
14. 14.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 5;
    console.log(x + y); (a) Error (b) 9 (c) 45
15. 15.⚡ What does this code show?
    let name = "Aman";
    alert("Well done, " + name + "!"); (a) name (b) Well done, Aman! (c) Well done, name! (d) Aman
16. 16.⚡ What does this code show?
    let name = "Aman";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) Aman (c) name (d) Hello, Aman!
17. 17.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .html (c) .css (d) .jpg
18. 18.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 3;
    console.log(x + y); (a) Error (b) 33 (c) 6
19. 19.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <style> (c) <js> (d) <script>
20. 20.⚡ What number does this code print?
    let books = 20;
    books = books + 20;
    books = books - 17;
    console.log(books);
21. 21.⚡ 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
22. 22.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 6;
    console.log(x + y); (a) 15 (b) 96 (c) Error
23. 23.⚡ Which JavaScript word repeats code? (a) if (b) for (c) let (d) alert()
24. 24.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 1;
    console.log(x + y); (a) 11 (b) 2 (c) Error
25. 25.⚡ What number does this code print?
    let a = 25;
    let b = 35;
    console.log(a + b);
26. 26.⚡ What does this code show?
    let name = "Aman";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Hello, Aman! (d) Aman
27. 27.⚡ What number does this code print?
    let a = 2;
    let b = 6;
    console.log(a * b);
28. 28.⚡ What number does this code print?
    let a = 46;
    let b = 20;
    console.log(a - b);
29. 29.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 2;
    console.log(x + y); (a) 82 (b) Error (c) 10
30. 30.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) Kabir (c) name (d) Hello, Kabir!
31. 31.⚡ What number does this code print?
    let a = 12;
    let b = 1;
    console.log(a + b);
32. 32.⚡ What number does this code print?
    let a = 33;
    let b = 6;
    console.log(a - b);
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 9;
    console.log(x + y); (a) 13 (b) Error (c) 49
34. 34.⚡ What does this code show?
    let name = "Arjun";
    console.log("Well done, " + name + "!"); (a) Well done, name! (b) Arjun (c) Well done, Arjun! (d) name
35. 35.⚡ What does this code show?
    let name = "Arjun";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Hello, Arjun! (d) Arjun
36. 36.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 8;
    console.log(x + y); (a) 48 (b) 12 (c) Error
37. 37.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 4;
    console.log(x + y); (a) 94 (b) Error (c) 13
38. 38.⚡ What does this code show?
    let name = "Meera";
    console.log("Welcome, " + name + "!"); (a) Welcome, Meera! (b) Meera (c) name (d) Welcome, name!
39. 39.⚡ What does this code show?
    let name = "Riya";
    alert("Hello, " + name + "!"); (a) name (b) Hello, Riya! (c) Riya (d) Hello, name!
40. 40.⚡ What does alert() show? (a) a table (b) a picture (c) a pop-up box (d) a new tab

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