JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 313 · 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 does this code print? (Look at the quotes!)
   let x = "2";
   let y = 6;
   console.log(x + y); (a) Error (b) 26 (c) 8
2. 2.⚡ What number does this code print?
   let a = 20;
   let b = 1;
   console.log(a + b);
3. 3.⚡ What number does this code print?
   let books = 30;
   books = books + 2;
   books = books - 23;
   console.log(books);
4. 4.⚡ What does JavaScript add to a web page? (a) the domain name (b) only colours (c) actions and changes (d) the page title
5. 5.⚡ Which tag holds JavaScript in a page? (a) <js> (b) <script> (c) <style> (d) <code>
6. 6.⚡ What number does this code print?
   let marks = 24;
   marks = marks + 7;
   marks = marks - 12;
   console.log(marks);
7. 7.⚡ Which JavaScript word shows a pop-up box? (a) for (b) if (c) alert() (d) let
8. 8.⚡ What number does this code print?
   let a = 2;
   let b = 10;
   console.log(a * b);
9. 9.⚡ Which JavaScript word writes in the console? (a) for (b) let (c) alert() (d) console.log()
10. 10.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .html (c) .css (d) .jpg
11. 11.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 1;
    console.log(x + y); (a) Error (b) 5 (c) 41
12. 12.⚡ What number does this code print?
    let score = 30;
    score = score + 6;
    score = score - 18;
    console.log(score);
13. 13.⚡ Which JavaScript word makes a new variable? (a) let (b) if (c) alert() (d) console.log()
14. 14.⚡ Which JavaScript word runs code when true? (a) for (b) console.log() (c) if (d) alert()
15. 15.⚡ What number does this code print?
    let score = 18;
    score = score + 6;
    score = score - 4;
    console.log(score);
16. 16.⚡ What number does this code print?
    let a = 30;
    let b = 22;
    console.log(a - b);
17. 17.⚡ 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
18. 18.⚡ Which word makes a new variable? (a) make (b) let (c) put (d) give
19. 19.⚡ What number does this code print?
    let books = 23;
    books = books + 19;
    books = books - 8;
    console.log(books);
20. 20.⚡ What number does this code print?
    let coins = 17;
    coins = coins + 11;
    coins = coins - 20;
    console.log(coins);
21. 21.⚡ What number does this code print?
    let a = 16;
    let b = 9;
    console.log(a - b);
22. 22.⚡ What number does this code print?
    let apples = 10;
    apples = apples + 18;
    apples = apples - 18;
    console.log(apples);
23. 23.⚡ What number does this code print?
    let apples = 5;
    apples = apples + 17;
    apples = apples - 19;
    console.log(apples);
24. 24.⚡ What number does this code print?
    let runs = 26;
    runs = runs + 6;
    runs = runs - 18;
    console.log(runs);
25. 25.⚡ What number does this code print?
    let a = 27;
    let b = 25;
    console.log(a - b);
26. 26.⚡ Which JavaScript word repeats code? (a) if (b) for (c) alert() (d) console.log()
27. 27.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hi, " + name + "!"); (a) Hi, name! (b) Kabir (c) Hi, Kabir! (d) name
28. 28.⚡ What number does this code print?
    let a = 10;
    let b = 14;
    console.log(a + b);
29. 29.⚡ What does this code show?
    let name = "Arjun";
    alert("Welcome, " + name + "!"); (a) name (b) Welcome, Arjun! (c) Welcome, name! (d) Arjun
30. 30.⚡ What does this code show?
    let name = "Kabir";
    console.log("Well done, " + name + "!"); (a) name (b) Kabir (c) Well done, Kabir! (d) Well done, name!
31. 31.⚡ 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
32. 32.⚡ What number does this code print?
    let a = 32;
    let b = 26;
    console.log(a + b);
33. 33.⚡ What number does this code print?
    let marks = 29;
    marks = marks + 7;
    marks = marks - 1;
    console.log(marks);
34. 34.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 7;
    console.log(x + y); (a) 37 (b) Error (c) 10
35. 35.⚡ What number does this code print?
    let coins = 11;
    coins = coins + 14;
    coins = coins - 23;
    console.log(coins);
36. 36.⚡ 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
37. 37.⚡ What does this code show?
    let name = "Zoya";
    alert("Welcome, " + name + "!"); (a) Welcome, name! (b) Zoya (c) name (d) Welcome, Zoya!
38. 38.⚡ What does this code show?
    let name = "Arjun";
    alert("Hi, " + name + "!"); (a) Arjun (b) Hi, Arjun! (c) Hi, name! (d) name
39. 39.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 4;
    console.log(x + y); (a) 7 (b) Error (c) 34
40. 40.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 9;
    console.log(x + y); (a) Error (b) 69 (c) 15

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