JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 215 · 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 runs code when true? (a) for (b) if (c) console.log() (d) alert()
2. 2.⚡ What does this code print? (Look at the quotes!)
   let x = "2";
   let y = 9;
   console.log(x + y); (a) 11 (b) 29 (c) Error
3. 3.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .html (c) .css (d) .jpg
4. 4.⚡ Which tag holds JavaScript in a page? (a) <js> (b) <script> (c) <style> (d) <code>
5. 5.⚡ What does this code print? (Look at the quotes!)
   let x = "9";
   let y = 6;
   console.log(x + y); (a) 15 (b) Error (c) 96
6. 6.⚡ What number does this code print?
   let a = 25;
   let b = 13;
   console.log(a - b);
7. 7.⚡ What number does this code print?
   let a = 53;
   let b = 31;
   console.log(a + b);
8. 8.⚡ Which JavaScript word makes a new variable? (a) if (b) let (c) alert() (d) for
9. 9.⚡ Which JavaScript word shows a pop-up box? (a) let (b) console.log() (c) alert() (d) if
10. 10.⚡ What does JavaScript add to a web page? (a) only colours (b) the page title (c) actions and changes (d) the domain name
11. 11.⚡ What number does this code print?
    let marks = 6;
    marks = marks + 19;
    marks = marks - 18;
    console.log(marks);
12. 12.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 6;
    console.log(x + y); (a) 36 (b) Error (c) 9
13. 13.⚡ Which JavaScript word writes in the console? (a) for (b) if (c) alert() (d) console.log()
14. 14.⚡ What number does this code print?
    let a = 5;
    let b = 8;
    console.log(a * b);
15. 15.⚡ Which word makes a new variable? (a) make (b) put (c) give (d) let
16. 16.⚡ What does this code show?
    let name = "Meera";
    alert("Hello, " + name + "!"); (a) Meera (b) name (c) Hello, Meera! (d) Hello, name!
17. 17.⚡ What number does this code print?
    let marks = 24;
    marks = marks + 9;
    marks = marks - 31;
    console.log(marks);
18. 18.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 5;
    console.log(x + y); (a) 7 (b) Error (c) 25
19. 19.⚡ What number does this code print?
    let a = 25;
    let b = 2;
    console.log(a + b);
20. 20.⚡ What number does this code print?
    let score = 17;
    score = score + 14;
    score = score - 14;
    console.log(score);
21. 21.⚡ 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
22. 22.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 7;
    console.log(x + y); (a) 57 (b) 12 (c) Error
23. 23.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 4;
    console.log(x + y); (a) 13 (b) Error (c) 94
24. 24.⚡ What does this code show?
    let name = "Aman";
    alert("Hello, " + name + "!"); (a) Hello, Aman! (b) Hello, name! (c) Aman (d) name
25. 25.⚡ What does alert() show? (a) a table (b) a new tab (c) a pop-up box (d) a picture
26. 26.⚡ Which JavaScript word repeats code? (a) alert() (b) for (c) if (d) console.log()
27. 27.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 1;
    console.log(x + y); (a) Error (b) 31 (c) 4
28. 28.⚡ What number does this code print?
    let a = 14;
    let b = 1;
    console.log(a + b);
29. 29.⚡ What does this code show?
    let name = "Riya";
    console.log("Hi, " + name + "!"); (a) name (b) Hi, name! (c) Riya (d) Hi, Riya!
30. 30.⚡ What does this code show?
    let name = "Arjun";
    alert("Hi, " + name + "!"); (a) name (b) Hi, name! (c) Arjun (d) Hi, Arjun!
31. 31.⚡ What number does this code print?
    let books = 11;
    books = books + 18;
    books = books - 11;
    console.log(books);
32. 32.⚡ What number does this code print?
    let marks = 24;
    marks = marks + 17;
    marks = marks - 21;
    console.log(marks);
33. 33.⚡ What number does this code print?
    let a = 49;
    let b = 16;
    console.log(a + b);
34. 34.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 4;
    console.log(x + y); (a) 9 (b) Error (c) 54
35. 35.⚡ What number does this code print?
    let a = 12;
    let b = 10;
    console.log(a * b);
36. 36.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hi, " + name + "!"); (a) Hi, Kabir! (b) name (c) Kabir (d) Hi, name!
37. 37.⚡ What number does this code print?
    let a = 6;
    let b = 10;
    console.log(a * b);
38. 38.⚡ What number does this code print?
    let runs = 7;
    runs = runs + 9;
    runs = runs - 6;
    console.log(runs);
39. 39.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 9;
    console.log(x + y); (a) Error (b) 12 (c) 39
40. 40.⚡ What number does this code print?
    let runs = 5;
    runs = runs + 3;
    runs = runs - 5;
    console.log(runs);

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