JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 857 · 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.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .jpg (c) .js (d) .html
2. 2.⚡ Where does console.log() show its output? (a) in the address bar (b) on the title bar (c) in the console (d) on the printer
3. 3.⚡ What does this code show?
   let name = "Arjun";
   alert("Welcome, " + name + "!"); (a) Arjun (b) Welcome, name! (c) Welcome, Arjun! (d) name
4. 4.⚡ What does this code print? (Look at the quotes!)
   let x = "4";
   let y = 5;
   console.log(x + y); (a) Error (b) 9 (c) 45
5. 5.⚡ What number does this code print?
   let a = 10;
   let b = 4;
   console.log(a * b);
6. 6.⚡ What does this code show?
   let name = "Arjun";
   alert("Hi, " + name + "!"); (a) Arjun (b) Hi, name! (c) Hi, Arjun! (d) name
7. 7.⚡ What does this code print? (Look at the quotes!)
   let x = "4";
   let y = 8;
   console.log(x + y); (a) Error (b) 48 (c) 12
8. 8.⚡ What number does this code print?
   let marks = 29;
   marks = marks + 12;
   marks = marks - 12;
   console.log(marks);
9. 9.⚡ What does this code show?
   let name = "Riya";
   alert("Hi, " + name + "!"); (a) Hi, Riya! (b) Riya (c) name (d) Hi, name!
10. 10.⚡ What number does this code print?
    let a = 7;
    let b = 8;
    console.log(a * b);
11. 11.⚡ What does alert() show? (a) a new tab (b) a picture (c) a pop-up box (d) a table
12. 12.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 9;
    console.log(x + y); (a) 69 (b) 15 (c) Error
13. 13.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 5;
    console.log(x + y); (a) 10 (b) Error (c) 55
14. 14.⚡ What does this code show?
    let name = "Zoya";
    console.log("Welcome, " + name + "!"); (a) Zoya (b) Welcome, name! (c) name (d) Welcome, Zoya!
15. 15.⚡ What number does this code print?
    let runs = 22;
    runs = runs + 17;
    runs = runs - 8;
    console.log(runs);
16. 16.⚡ What number does this code print?
    let a = 28;
    let b = 3;
    console.log(a - b);
17. 17.⚡ What number does this code print?
    let a = 12;
    let b = 10;
    console.log(a * b);
18. 18.⚡ Which JavaScript word runs code when true? (a) for (b) alert() (c) if (d) let
19. 19.⚡ What number does this code print?
    let runs = 28;
    runs = runs + 4;
    runs = runs - 19;
    console.log(runs);
20. 20.⚡ What number does this code print?
    let a = 47;
    let b = 39;
    console.log(a + b);
21. 21.⚡ What number does this code print?
    let a = 28;
    let b = 11;
    console.log(a - b);
22. 22.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 9;
    console.log(x + y); (a) 10 (b) 19 (c) Error
23. 23.⚡ What does this code show?
    let name = "Meera";
    console.log("Well done, " + name + "!"); (a) Well done, Meera! (b) Well done, name! (c) Meera (d) name
24. 24.⚡ Which JavaScript word repeats code? (a) let (b) if (c) for (d) console.log()
25. 25.⚡ Which JavaScript word shows a pop-up box? (a) if (b) console.log() (c) alert() (d) let
26. 26.⚡ What does this code show?
    let name = "Kabir";
    alert("Hi, " + name + "!"); (a) name (b) Kabir (c) Hi, name! (d) Hi, Kabir!
27. 27.⚡ Which JavaScript word writes in the console? (a) alert() (b) let (c) console.log() (d) if
28. 28.⚡ What number does this code print?
    let a = 45;
    let b = 9;
    console.log(a - b);
29. 29.⚡ What number does this code print?
    let books = 24;
    books = books + 4;
    books = books - 7;
    console.log(books);
30. 30.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 9;
    console.log(x + y); (a) 49 (b) 13 (c) Error
31. 31.⚡ What number does this code print?
    let a = 24;
    let b = 6;
    console.log(a - b);
32. 32.⚡ Which tag holds JavaScript in a page? (a) <js> (b) <script> (c) <code> (d) <style>
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 3;
    console.log(x + y); (a) 4 (b) Error (c) 13
34. 34.⚡ What does this code show?
    let name = "Arjun";
    console.log("Well done, " + name + "!"); (a) Arjun (b) Well done, name! (c) name (d) Well done, Arjun!
35. 35.⚡ What number does this code print?
    let a = 2;
    let b = 12;
    console.log(a * b);
36. 36.⚡ What number does this code print?
    let books = 6;
    books = books + 9;
    books = books - 4;
    console.log(books);
37. 37.⚡ What does this code show?
    let name = "Kabir";
    console.log("Well done, " + name + "!"); (a) Well done, name! (b) Kabir (c) Well done, Kabir! (d) name
38. 38.⚡ Which JavaScript word makes a new variable? (a) let (b) console.log() (c) for (d) alert()
39. 39.⚡ What number does this code print?
    let a = 32;
    let b = 18;
    console.log(a - b);
40. 40.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 4;
    console.log(x + y); (a) 8 (b) Error (c) 44

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