JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 272 · 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 JavaScript word writes in the console? (a) let (b) console.log() (c) alert() (d) if
2. 2.⚡ What does alert() show? (a) a new tab (b) a pop-up box (c) a table (d) a picture
3. 3.⚡ What does this code print? (Look at the quotes!)
   let x = "1";
   let y = 3;
   console.log(x + y); (a) 4 (b) 13 (c) Error
4. 4.⚡ Which JavaScript word runs code when true? (a) for (b) if (c) let (d) console.log()
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.⚡ Which JavaScript word repeats code? (a) for (b) let (c) console.log() (d) alert()
7. 7.⚡ What does this code print? (Look at the quotes!)
   let x = "9";
   let y = 1;
   console.log(x + y); (a) Error (b) 91 (c) 10
8. 8.⚡ What does JavaScript add to a web page? (a) the page title (b) actions and changes (c) only colours (d) the domain name
9. 9.⚡ Which tag holds JavaScript in a page? (a) <js> (b) <style> (c) <code> (d) <script>
10. 10.⚡ What does this code show?
    let name = "Arjun";
    alert("Well done, " + name + "!"); (a) name (b) Arjun (c) Well done, Arjun! (d) Well done, name!
11. 11.⚡ What does this code show?
    let name = "Riya";
    alert("Hi, " + name + "!"); (a) Hi, name! (b) Riya (c) name (d) Hi, Riya!
12. 12.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 6;
    console.log(x + y); (a) 13 (b) Error (c) 76
13. 13.⚡ What number does this code print?
    let a = 10;
    let b = 9;
    console.log(a * b);
14. 14.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hi, " + name + "!"); (a) Hi, Kabir! (b) name (c) Kabir (d) Hi, name!
15. 15.⚡ What number does this code print?
    let a = 48;
    let b = 3;
    console.log(a - b);
16. 16.⚡ Which JavaScript word makes a new variable? (a) console.log() (b) for (c) if (d) let
17. 17.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .html (c) .jpg (d) .js
18. 18.⚡ What number does this code print?
    let books = 24;
    books = books + 9;
    books = books - 29;
    console.log(books);
19. 19.⚡ What number does this code print?
    let a = 8;
    let b = 5;
    console.log(a * b);
20. 20.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 7;
    console.log(x + y); (a) 47 (b) 11 (c) Error
21. 21.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hello, " + name + "!"); (a) Hello, Kabir! (b) Kabir (c) name (d) Hello, name!
22. 22.⚡ Which JavaScript word shows a pop-up box? (a) let (b) for (c) if (d) alert()
23. 23.⚡ What number does this code print?
    let a = 27;
    let b = 5;
    console.log(a - b);
24. 24.⚡ What number does this code print?
    let score = 28;
    score = score + 7;
    score = score - 12;
    console.log(score);
25. 25.⚡ What does this code show?
    let name = "Riya";
    alert("Well done, " + name + "!"); (a) name (b) Riya (c) Well done, Riya! (d) Well done, name!
26. 26.⚡ What number does this code print?
    let a = 17;
    let b = 18;
    console.log(a + b);
27. 27.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 9;
    console.log(x + y); (a) 18 (b) 99 (c) Error
28. 28.⚡ What does this code show?
    let name = "Riya";
    console.log("Welcome, " + name + "!"); (a) Riya (b) Welcome, name! (c) name (d) Welcome, Riya!
29. 29.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 4;
    console.log(x + y); (a) Error (b) 13 (c) 94
30. 30.⚡ Which word makes a new variable? (a) let (b) make (c) give (d) put
31. 31.⚡ What number does this code print?
    let runs = 19;
    runs = runs + 8;
    runs = runs - 14;
    console.log(runs);
32. 32.⚡ Where does console.log() show its output? (a) in the console (b) on the title bar (c) in the address bar (d) on the printer
33. 33.⚡ What number does this code print?
    let a = 30;
    let b = 5;
    console.log(a - b);
34. 34.⚡ What number does this code print?
    let a = 4;
    let b = 7;
    console.log(a * b);
35. 35.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 7;
    console.log(x + y); (a) Error (b) 15 (c) 87
36. 36.⚡ What number does this code print?
    let a = 2;
    let b = 9;
    console.log(a * b);
37. 37.⚡ What number does this code print?
    let marks = 20;
    marks = marks + 7;
    marks = marks - 17;
    console.log(marks);
38. 38.⚡ What number does this code print?
    let marks = 25;
    marks = marks + 19;
    marks = marks - 40;
    console.log(marks);
39. 39.⚡ What does this code show?
    let name = "Riya";
    alert("Hello, " + name + "!"); (a) name (b) Riya (c) Hello, Riya! (d) Hello, name!
40. 40.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 3;
    console.log(x + y); (a) 8 (b) Error (c) 53

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