JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 648 · 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 = "4";
   let y = 1;
   console.log(x + y); (a) 41 (b) Error (c) 5
3. 3.⚡ What does this code print? (Look at the quotes!)
   let x = "4";
   let y = 3;
   console.log(x + y); (a) 7 (b) 43 (c) Error
4. 4.⚡ Which JavaScript word shows a pop-up box? (a) if (b) let (c) alert() (d) console.log()
5. 5.⚡ Which JavaScript word repeats code? (a) if (b) console.log() (c) alert() (d) for
6. 6.⚡ What does alert() show? (a) a new tab (b) a picture (c) a pop-up box (d) a table
7. 7.⚡ Which word makes a new variable? (a) put (b) make (c) let (d) give
8. 8.⚡ What number does this code print?
   let marks = 17;
   marks = marks + 18;
   marks = marks - 18;
   console.log(marks);
9. 9.⚡ What does this code show?
   let name = "Riya";
   alert("Welcome, " + name + "!"); (a) Welcome, Riya! (b) name (c) Welcome, name! (d) Riya
10. 10.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 3;
    console.log(x + y); (a) 10 (b) 73 (c) Error
11. 11.⚡ What number does this code print?
    let a = 26;
    let b = 35;
    console.log(a + b);
12. 12.⚡ Which JavaScript word runs code when true? (a) for (b) console.log() (c) if (d) let
13. 13.⚡ What does this code show?
    let name = "Riya";
    console.log("Hello, " + name + "!"); (a) Hello, Riya! (b) Riya (c) Hello, name! (d) name
14. 14.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 7;
    console.log(x + y); (a) 15 (b) Error (c) 87
15. 15.⚡ What number does this code print?
    let a = 32;
    let b = 33;
    console.log(a + b);
16. 16.⚡ What does this code show?
    let name = "Aman";
    console.log("Hi, " + name + "!"); (a) Aman (b) Hi, Aman! (c) name (d) Hi, name!
17. 17.⚡ Which JavaScript word writes in the console? (a) console.log() (b) for (c) alert() (d) let
18. 18.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hello, " + name + "!"); (a) name (b) Hello, Kabir! (c) Hello, name! (d) Kabir
19. 19.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 1;
    console.log(x + y); (a) 61 (b) Error (c) 7
20. 20.⚡ What number does this code print?
    let score = 25;
    score = score + 5;
    score = score - 29;
    console.log(score);
21. 21.⚡ What does this code show?
    let name = "Aman";
    alert("Welcome, " + name + "!"); (a) Aman (b) name (c) Welcome, Aman! (d) Welcome, name!
22. 22.⚡ What number does this code print?
    let apples = 20;
    apples = apples + 2;
    apples = apples - 16;
    console.log(apples);
23. 23.⚡ What number does this code print?
    let a = 2;
    let b = 3;
    console.log(a * b);
24. 24.⚡ Where does console.log() show its output? (a) in the console (b) in the address bar (c) on the title bar (d) on the printer
25. 25.⚡ What does JavaScript add to a web page? (a) only colours (b) the page title (c) the domain name (d) actions and changes
26. 26.⚡ A JavaScript file usually ends with which extension? (a) .jpg (b) .html (c) .css (d) .js
27. 27.⚡ What number does this code print?
    let a = 38;
    let b = 21;
    console.log(a + b);
28. 28.⚡ What does this code show?
    let name = "Zoya";
    alert("Hello, " + name + "!"); (a) name (b) Zoya (c) Hello, name! (d) Hello, Zoya!
29. 29.⚡ What number does this code print?
    let apples = 19;
    apples = apples + 6;
    apples = apples - 17;
    console.log(apples);
30. 30.⚡ What number does this code print?
    let score = 9;
    score = score + 13;
    score = score - 11;
    console.log(score);
31. 31.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 5;
    console.log(x + y); (a) 7 (b) 25 (c) Error
32. 32.⚡ What number does this code print?
    let books = 11;
    books = books + 18;
    books = books - 4;
    console.log(books);
33. 33.⚡ What number does this code print?
    let score = 26;
    score = score + 3;
    score = score - 9;
    console.log(score);
34. 34.⚡ Which JavaScript word makes a new variable? (a) alert() (b) if (c) for (d) let
35. 35.⚡ What number does this code print?
    let a = 51;
    let b = 7;
    console.log(a + b);
36. 36.⚡ What number does this code print?
    let coins = 14;
    coins = coins + 6;
    coins = coins - 2;
    console.log(coins);
37. 37.⚡ What number does this code print?
    let marks = 10;
    marks = marks + 9;
    marks = marks - 12;
    console.log(marks);
38. 38.⚡ What number does this code print?
    let a = 4;
    let b = 2;
    console.log(a * b);
39. 39.⚡ What number does this code print?
    let coins = 19;
    coins = coins + 12;
    coins = coins - 4;
    console.log(coins);
40. 40.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 3;
    console.log(x + y); (a) 83 (b) 11 (c) Error

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