JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 655 · 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.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <js> (c) <script> (d) <style>
3. 3.⚡ What number does this code print?
   let books = 22;
   books = books + 4;
   books = books - 26;
   console.log(books);
4. 4.⚡ Which JavaScript word makes a new variable? (a) let (b) alert() (c) if (d) console.log()
5. 5.⚡ What does this code print? (Look at the quotes!)
   let x = "1";
   let y = 7;
   console.log(x + y); (a) Error (b) 8 (c) 17
6. 6.⚡ What does this code print? (Look at the quotes!)
   let x = "7";
   let y = 5;
   console.log(x + y); (a) Error (b) 12 (c) 75
7. 7.⚡ What does JavaScript add to a web page? (a) the page title (b) only colours (c) the domain name (d) actions and changes
8. 8.⚡ Where does console.log() show its output? (a) on the title bar (b) on the printer (c) in the console (d) in the address bar
9. 9.⚡ Which JavaScript word repeats code? (a) alert() (b) let (c) if (d) for
10. 10.⚡ What does this code show?
    let name = "Arjun";
    console.log("Hi, " + name + "!"); (a) Hi, Arjun! (b) Arjun (c) name (d) Hi, name!
11. 11.⚡ What number does this code print?
    let a = 5;
    let b = 10;
    console.log(a * b);
12. 12.⚡ Which JavaScript word shows a pop-up box? (a) let (b) console.log() (c) alert() (d) for
13. 13.⚡ What does this code show?
    let name = "Arjun";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) Arjun (c) Welcome, Arjun! (d) name
14. 14.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 4;
    console.log(x + y); (a) 5 (b) 14 (c) Error
15. 15.⚡ What does this code show?
    let name = "Arjun";
    console.log("Well done, " + name + "!"); (a) Well done, Arjun! (b) Arjun (c) name (d) Well done, name!
16. 16.⚡ What does alert() show? (a) a new tab (b) a picture (c) a pop-up box (d) a table
17. 17.⚡ Which JavaScript word runs code when true? (a) console.log() (b) if (c) for (d) alert()
18. 18.⚡ What does this code show?
    let name = "Meera";
    console.log("Hi, " + name + "!"); (a) Hi, Meera! (b) Hi, name! (c) Meera (d) name
19. 19.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 8;
    console.log(x + y); (a) Error (b) 38 (c) 11
20. 20.⚡ What number does this code print?
    let score = 21;
    score = score + 4;
    score = score - 24;
    console.log(score);
21. 21.⚡ Which JavaScript word writes in the console? (a) alert() (b) console.log() (c) for (d) if
22. 22.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 3;
    console.log(x + y); (a) 5 (b) Error (c) 23
23. 23.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 1;
    console.log(x + y); (a) Error (b) 21 (c) 3
24. 24.⚡ What does this code show?
    let name = "Riya";
    alert("Welcome, " + name + "!"); (a) Welcome, Riya! (b) name (c) Welcome, name! (d) Riya
25. 25.⚡ What number does this code print?
    let runs = 15;
    runs = runs + 11;
    runs = runs - 6;
    console.log(runs);
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 6;
    console.log(x + y); (a) 96 (b) Error (c) 15
27. 27.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 7;
    console.log(x + y); (a) 27 (b) Error (c) 9
28. 28.⚡ What number does this code print?
    let runs = 26;
    runs = runs + 9;
    runs = runs - 28;
    console.log(runs);
29. 29.⚡ What number does this code print?
    let books = 29;
    books = books + 2;
    books = books - 16;
    console.log(books);
30. 30.⚡ What does this code show?
    let name = "Zoya";
    console.log("Hi, " + name + "!"); (a) Zoya (b) Hi, Zoya! (c) Hi, name! (d) name
31. 31.⚡ What does this code show?
    let name = "Aman";
    console.log("Hi, " + name + "!"); (a) Aman (b) Hi, name! (c) name (d) Hi, Aman!
32. 32.⚡ What number does this code print?
    let a = 59;
    let b = 10;
    console.log(a + b);
33. 33.⚡ What number does this code print?
    let runs = 22;
    runs = runs + 4;
    runs = runs - 16;
    console.log(runs);
34. 34.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 9;
    console.log(x + y); (a) 69 (b) Error (c) 15
35. 35.⚡ What number does this code print?
    let marks = 30;
    marks = marks + 13;
    marks = marks - 35;
    console.log(marks);
36. 36.⚡ What number does this code print?
    let a = 2;
    let b = 7;
    console.log(a * b);
37. 37.⚡ What number does this code print?
    let a = 3;
    let b = 4;
    console.log(a * b);
38. 38.⚡ What number does this code print?
    let a = 57;
    let b = 7;
    console.log(a + b);
39. 39.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 3;
    console.log(x + y); (a) 7 (b) Error (c) 43
40. 40.⚡ What number does this code print?
    let a = 4;
    let b = 8;
    console.log(a * b);

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