JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 470 · 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 = 25;
   apples = apples + 3;
   apples = apples - 27;
   console.log(apples);
2. 2.⚡ Which JavaScript word makes a new variable? (a) alert() (b) let (c) if (d) console.log()
3. 3.⚡ What number does this code print?
   let score = 26;
   score = score + 3;
   score = score - 5;
   console.log(score);
4. 4.⚡ Where does console.log() show its output? (a) in the console (b) in the address bar (c) on the printer (d) on the title bar
5. 5.⚡ Which JavaScript word runs code when true? (a) if (b) for (c) alert() (d) let
6. 6.⚡ A JavaScript file usually ends with which extension? (a) .jpg (b) .js (c) .html (d) .css
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 = 19;
   let b = 30;
   console.log(a + b);
9. 9.⚡ What number does this code print?
   let a = 41;
   let b = 12;
   console.log(a - b);
10. 10.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 1;
    console.log(x + y); (a) Error (b) 41 (c) 5
11. 11.⚡ Which JavaScript word repeats code? (a) let (b) alert() (c) console.log() (d) for
12. 12.⚡ What does JavaScript add to a web page? (a) the domain name (b) the page title (c) actions and changes (d) only colours
13. 13.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 4;
    console.log(x + y); (a) 10 (b) Error (c) 64
14. 14.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <style> (c) <js> (d) <script>
15. 15.⚡ What number does this code print?
    let books = 28;
    books = books + 8;
    books = books - 15;
    console.log(books);
16. 16.⚡ What number does this code print?
    let score = 14;
    score = score + 8;
    score = score - 21;
    console.log(score);
17. 17.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 5;
    console.log(x + y); (a) 85 (b) 13 (c) Error
18. 18.⚡ What number does this code print?
    let a = 3;
    let b = 3;
    console.log(a * b);
19. 19.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 6;
    console.log(x + y); (a) 13 (b) Error (c) 76
20. 20.⚡ What does this code show?
    let name = "Meera";
    alert("Hi, " + name + "!"); (a) name (b) Meera (c) Hi, name! (d) Hi, Meera!
21. 21.⚡ What number does this code print?
    let a = 39;
    let b = 24;
    console.log(a + b);
22. 22.⚡ Which word makes a new variable? (a) give (b) make (c) put (d) let
23. 23.⚡ What number does this code print?
    let a = 7;
    let b = 6;
    console.log(a * b);
24. 24.⚡ What number does this code print?
    let coins = 8;
    coins = coins + 9;
    coins = coins - 17;
    console.log(coins);
25. 25.⚡ What number does this code print?
    let a = 60;
    let b = 26;
    console.log(a - b);
26. 26.⚡ What does this code show?
    let name = "Riya";
    console.log("Hi, " + name + "!"); (a) Hi, name! (b) name (c) Riya (d) Hi, Riya!
27. 27.⚡ What number does this code print?
    let a = 8;
    let b = 3;
    console.log(a * b);
28. 28.⚡ What number does this code print?
    let runs = 6;
    runs = runs + 2;
    runs = runs - 6;
    console.log(runs);
29. 29.⚡ What number does this code print?
    let a = 49;
    let b = 19;
    console.log(a + b);
30. 30.⚡ What number does this code print?
    let a = 12;
    let b = 12;
    console.log(a * b);
31. 31.⚡ What number does this code print?
    let score = 5;
    score = score + 3;
    score = score - 8;
    console.log(score);
32. 32.⚡ What number does this code print?
    let a = 14;
    let b = 13;
    console.log(a - b);
33. 33.⚡ What does alert() show? (a) a new tab (b) a table (c) a pop-up box (d) a picture
34. 34.⚡ What does this code show?
    let name = "Kabir";
    alert("Welcome, " + name + "!"); (a) Welcome, Kabir! (b) Welcome, name! (c) Kabir (d) name
35. 35.⚡ What does this code show?
    let name = "Riya";
    alert("Hi, " + name + "!"); (a) Hi, Riya! (b) name (c) Riya (d) Hi, name!
36. 36.⚡ What does this code show?
    let name = "Zoya";
    console.log("Well done, " + name + "!"); (a) Well done, name! (b) Zoya (c) name (d) Well done, Zoya!
37. 37.⚡ What number does this code print?
    let books = 9;
    books = books + 16;
    books = books - 21;
    console.log(books);
38. 38.⚡ What number does this code print?
    let a = 7;
    let b = 32;
    console.log(a + b);
39. 39.⚡ What number does this code print?
    let score = 21;
    score = score + 14;
    score = score - 27;
    console.log(score);
40. 40.⚡ Which JavaScript word writes in the console? (a) if (b) alert() (c) for (d) console.log()

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