JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 52 · 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 score = 12;
   score = score + 7;
   score = score - 7;
   console.log(score);
2. 2.⚡ What number does this code print?
   let a = 37;
   let b = 35;
   console.log(a - b);
3. 3.⚡ Which JavaScript word runs code when true? (a) if (b) console.log() (c) for (d) alert()
4. 4.⚡ Which JavaScript word repeats code? (a) alert() (b) let (c) console.log() (d) for
5. 5.⚡ What number does this code print?
   let a = 8;
   let b = 2;
   console.log(a * b);
6. 6.⚡ What does JavaScript add to a web page? (a) the page title (b) only colours (c) the domain name (d) actions and changes
7. 7.⚡ Which JavaScript word makes a new variable? (a) if (b) alert() (c) let (d) for
8. 8.⚡ What does this code print? (Look at the quotes!)
   let x = "6";
   let y = 4;
   console.log(x + y); (a) Error (b) 10 (c) 64
9. 9.⚡ What does this code show?
   let name = "Meera";
   alert("Well done, " + name + "!"); (a) Meera (b) Well done, name! (c) name (d) Well done, Meera!
10. 10.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 8;
    console.log(x + y); (a) 15 (b) 78 (c) Error
11. 11.⚡ Which tag holds JavaScript in a page? (a) <script> (b) <style> (c) <code> (d) <js>
12. 12.⚡ Which JavaScript word shows a pop-up box? (a) console.log() (b) alert() (c) if (d) for
13. 13.⚡ What number does this code print?
    let marks = 20;
    marks = marks + 2;
    marks = marks - 3;
    console.log(marks);
14. 14.⚡ What does this code show?
    let name = "Kabir";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) Welcome, Kabir! (c) Kabir (d) name
15. 15.⚡ What number does this code print?
    let a = 32;
    let b = 18;
    console.log(a + b);
16. 16.⚡ A JavaScript file usually ends with which extension? (a) .jpg (b) .css (c) .html (d) .js
17. 17.⚡ What number does this code print?
    let runs = 23;
    runs = runs + 5;
    runs = runs - 9;
    console.log(runs);
18. 18.⚡ What number does this code print?
    let a = 57;
    let b = 20;
    console.log(a - b);
19. 19.⚡ What number does this code print?
    let books = 7;
    books = books + 10;
    books = books - 12;
    console.log(books);
20. 20.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 3;
    console.log(x + y); (a) Error (b) 7 (c) 43
21. 21.⚡ What does this code show?
    let name = "Zoya";
    alert("Welcome, " + name + "!"); (a) Welcome, name! (b) Zoya (c) name (d) Welcome, Zoya!
22. 22.⚡ What number does this code print?
    let books = 9;
    books = books + 8;
    books = books - 7;
    console.log(books);
23. 23.⚡ What number does this code print?
    let a = 4;
    let b = 8;
    console.log(a * b);
24. 24.⚡ What number does this code print?
    let a = 29;
    let b = 29;
    console.log(a - b);
25. 25.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 9;
    console.log(x + y); (a) 13 (b) Error (c) 49
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 7;
    console.log(x + y); (a) Error (b) 17 (c) 8
27. 27.⚡ What number does this code print?
    let runs = 24;
    runs = runs + 4;
    runs = runs - 13;
    console.log(runs);
28. 28.⚡ What number does this code print?
    let a = 10;
    let b = 5;
    console.log(a * b);
29. 29.⚡ Where does console.log() show its output? (a) on the title bar (b) in the address bar (c) on the printer (d) in the console
30. 30.⚡ Which word makes a new variable? (a) make (b) put (c) let (d) give
31. 31.⚡ What number does this code print?
    let a = 15;
    let b = 5;
    console.log(a + b);
32. 32.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 3;
    console.log(x + y); (a) 83 (b) Error (c) 11
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 9;
    console.log(x + y); (a) Error (b) 39 (c) 12
34. 34.⚡ Which JavaScript word writes in the console? (a) for (b) if (c) let (d) console.log()
35. 35.⚡ What number does this code print?
    let a = 11;
    let b = 12;
    console.log(a * b);
36. 36.⚡ What number does this code print?
    let runs = 22;
    runs = runs + 16;
    runs = runs - 15;
    console.log(runs);
37. 37.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 7;
    console.log(x + y); (a) 9 (b) Error (c) 27
38. 38.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 2;
    console.log(x + y); (a) 82 (b) 10 (c) Error
39. 39.⚡ What number does this code print?
    let a = 29;
    let b = 15;
    console.log(a - b);
40. 40.⚡ What number does this code print?
    let a = 7;
    let b = 4;
    console.log(a * b);

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