JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 863 · 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.⚡ Which tag holds JavaScript in a page? (a) <script> (b) <style> (c) <code> (d) <js>
2. 2.⚡ What does this code print? (Look at the quotes!)
   let x = "3";
   let y = 7;
   console.log(x + y); (a) 10 (b) 37 (c) Error
3. 3.⚡ What does alert() show? (a) a picture (b) a new tab (c) a pop-up box (d) a table
4. 4.⚡ What number does this code print?
   let coins = 28;
   coins = coins + 2;
   coins = coins - 15;
   console.log(coins);
5. 5.⚡ What does this code print? (Look at the quotes!)
   let x = "5";
   let y = 5;
   console.log(x + y); (a) Error (b) 10 (c) 55
6. 6.⚡ What does this code print? (Look at the quotes!)
   let x = "7";
   let y = 7;
   console.log(x + y); (a) 14 (b) Error (c) 77
7. 7.⚡ What does this code print? (Look at the quotes!)
   let x = "1";
   let y = 9;
   console.log(x + y); (a) Error (b) 19 (c) 10
8. 8.⚡ Which JavaScript word makes a new variable? (a) let (b) if (c) for (d) alert()
9. 9.⚡ What does this code print? (Look at the quotes!)
   let x = "2";
   let y = 9;
   console.log(x + y); (a) Error (b) 29 (c) 11
10. 10.⚡ What number does this code print?
    let a = 12;
    let b = 21;
    console.log(a + b);
11. 11.⚡ What number does this code print?
    let coins = 29;
    coins = coins + 6;
    coins = coins - 27;
    console.log(coins);
12. 12.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hello, " + name + "!"); (a) Kabir (b) Hello, name! (c) name (d) Hello, Kabir!
13. 13.⚡ Which JavaScript word runs code when true? (a) if (b) let (c) console.log() (d) alert()
14. 14.⚡ What number does this code print?
    let a = 20;
    let b = 14;
    console.log(a - b);
15. 15.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 6;
    console.log(x + y); (a) 11 (b) Error (c) 56
16. 16.⚡ What number does this code print?
    let score = 14;
    score = score + 6;
    score = score - 7;
    console.log(score);
17. 17.⚡ What does this code show?
    let name = "Zoya";
    alert("Welcome, " + name + "!"); (a) Welcome, Zoya! (b) Welcome, name! (c) name (d) Zoya
18. 18.⚡ Which word makes a new variable? (a) put (b) make (c) give (d) let
19. 19.⚡ What number does this code print?
    let marks = 16;
    marks = marks + 14;
    marks = marks - 4;
    console.log(marks);
20. 20.⚡ What number does this code print?
    let marks = 21;
    marks = marks + 11;
    marks = marks - 17;
    console.log(marks);
21. 21.⚡ What does this code show?
    let name = "Aman";
    alert("Welcome, " + name + "!"); (a) name (b) Welcome, Aman! (c) Welcome, name! (d) Aman
22. 22.⚡ Where does console.log() show its output? (a) on the printer (b) in the address bar (c) on the title bar (d) in the console
23. 23.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .html (c) .css (d) .jpg
24. 24.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 2;
    console.log(x + y); (a) Error (b) 6 (c) 42
25. 25.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 1;
    console.log(x + y); (a) 21 (b) 3 (c) Error
26. 26.⚡ What number does this code print?
    let score = 8;
    score = score + 10;
    score = score - 5;
    console.log(score);
27. 27.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hi, " + name + "!"); (a) Hi, name! (b) name (c) Kabir (d) Hi, Kabir!
28. 28.⚡ What number does this code print?
    let coins = 7;
    coins = coins + 7;
    coins = coins - 4;
    console.log(coins);
29. 29.⚡ What does JavaScript add to a web page? (a) only colours (b) the page title (c) actions and changes (d) the domain name
30. 30.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) let (c) if (d) console.log()
31. 31.⚡ What number does this code print?
    let books = 12;
    books = books + 16;
    books = books - 1;
    console.log(books);
32. 32.⚡ What number does this code print?
    let a = 6;
    let b = 23;
    console.log(a + b);
33. 33.⚡ What number does this code print?
    let a = 3;
    let b = 12;
    console.log(a * b);
34. 34.⚡ What number does this code print?
    let a = 12;
    let b = 11;
    console.log(a - b);
35. 35.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 6;
    console.log(x + y); (a) 13 (b) 76 (c) Error
36. 36.⚡ What does this code show?
    let name = "Riya";
    alert("Welcome, " + name + "!"); (a) Welcome, name! (b) Welcome, Riya! (c) Riya (d) name
37. 37.⚡ What number does this code print?
    let coins = 30;
    coins = coins + 17;
    coins = coins - 46;
    console.log(coins);
38. 38.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 5;
    console.log(x + y); (a) Error (b) 14 (c) 95
39. 39.⚡ What does this code show?
    let name = "Kabir";
    alert("Well done, " + name + "!"); (a) name (b) Well done, name! (c) Kabir (d) Well done, Kabir!
40. 40.⚡ What does this code show?
    let name = "Meera";
    console.log("Welcome, " + name + "!"); (a) Welcome, Meera! (b) name (c) Welcome, name! (d) Meera

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