JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 53 · 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 apples = 29;
   apples = apples + 2;
   apples = apples - 15;
   console.log(apples);
2. 2.⚡ What does this code print? (Look at the quotes!)
   let x = "8";
   let y = 2;
   console.log(x + y); (a) Error (b) 82 (c) 10
3. 3.⚡ What does alert() show? (a) a new tab (b) a picture (c) a pop-up box (d) a table
4. 4.⚡ What number does this code print?
   let a = 3;
   let b = 10;
   console.log(a * b);
5. 5.⚡ Which JavaScript word shows a pop-up box? (a) let (b) console.log() (c) if (d) alert()
6. 6.⚡ What does JavaScript add to a web page? (a) the domain name (b) actions and changes (c) the page title (d) only colours
7. 7.⚡ Which JavaScript word runs code when true? (a) let (b) alert() (c) if (d) console.log()
8. 8.⚡ What does this code show?
   let name = "Arjun";
   console.log("Hello, " + name + "!"); (a) Hello, name! (b) Hello, Arjun! (c) Arjun (d) name
9. 9.⚡ 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
10. 10.⚡ Which JavaScript word repeats code? (a) console.log() (b) let (c) if (d) for
11. 11.⚡ What does this code show?
    let name = "Zoya";
    console.log("Hi, " + name + "!"); (a) Zoya (b) Hi, name! (c) Hi, Zoya! (d) name
12. 12.⚡ Which JavaScript word writes in the console? (a) alert() (b) let (c) console.log() (d) for
13. 13.⚡ What does this code show?
    let name = "Meera";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Hello, Meera! (d) Meera
14. 14.⚡ What number does this code print?
    let a = 7;
    let b = 10;
    console.log(a + b);
15. 15.⚡ What number does this code print?
    let apples = 7;
    apples = apples + 17;
    apples = apples - 4;
    console.log(apples);
16. 16.⚡ 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
17. 17.⚡ What number does this code print?
    let runs = 20;
    runs = runs + 17;
    runs = runs - 30;
    console.log(runs);
18. 18.⚡ What does this code show?
    let name = "Arjun";
    alert("Hello, " + name + "!"); (a) Arjun (b) Hello, name! (c) name (d) Hello, Arjun!
19. 19.⚡ Which word makes a new variable? (a) let (b) put (c) make (d) give
20. 20.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 5;
    console.log(x + y); (a) 8 (b) Error (c) 35
21. 21.⚡ What number does this code print?
    let a = 7;
    let b = 34;
    console.log(a + b);
22. 22.⚡ 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
23. 23.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 4;
    console.log(x + y); (a) 64 (b) Error (c) 10
24. 24.⚡ What number does this code print?
    let a = 12;
    let b = 11;
    console.log(a - b);
25. 25.⚡ What number does this code print?
    let runs = 23;
    runs = runs + 13;
    runs = runs - 15;
    console.log(runs);
26. 26.⚡ What does this code show?
    let name = "Arjun";
    console.log("Well done, " + name + "!"); (a) Well done, name! (b) name (c) Arjun (d) Well done, Arjun!
27. 27.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 5;
    console.log(x + y); (a) 45 (b) 9 (c) Error
28. 28.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .css (c) .jpg (d) .js
29. 29.⚡ What number does this code print?
    let a = 24;
    let b = 14;
    console.log(a - b);
30. 30.⚡ What number does this code print?
    let a = 10;
    let b = 9;
    console.log(a * b);
31. 31.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <script> (c) <js> (d) <style>
32. 32.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 8;
    console.log(x + y); (a) Error (b) 28 (c) 10
33. 33.⚡ What does this code show?
    let name = "Aman";
    console.log("Welcome, " + name + "!"); (a) Aman (b) Welcome, name! (c) Welcome, Aman! (d) name
34. 34.⚡ What number does this code print?
    let marks = 29;
    marks = marks + 10;
    marks = marks - 13;
    console.log(marks);
35. 35.⚡ Which JavaScript word makes a new variable? (a) if (b) let (c) console.log() (d) alert()
36. 36.⚡ What number does this code print?
    let a = 19;
    let b = 6;
    console.log(a - b);
37. 37.⚡ 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
38. 38.⚡ What number does this code print?
    let books = 8;
    books = books + 13;
    books = books - 19;
    console.log(books);
39. 39.⚡ What number does this code print?
    let books = 18;
    books = books + 15;
    books = books - 8;
    console.log(books);
40. 40.⚡ What number does this code print?
    let apples = 11;
    apples = apples + 18;
    apples = apples - 12;
    console.log(apples);

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