JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 674 · 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 books = 16;
   books = books + 3;
   books = books - 4;
   console.log(books);
2. 2.⚡ Which JavaScript word shows a pop-up box? (a) let (b) alert() (c) console.log() (d) for
3. 3.⚡ What number does this code print?
   let score = 26;
   score = score + 7;
   score = score - 8;
   console.log(score);
4. 4.⚡ What number does this code print?
   let a = 59;
   let b = 23;
   console.log(a - b);
5. 5.⚡ What does this code show?
   let name = "Riya";
   alert("Hello, " + name + "!"); (a) Hello, Riya! (b) Riya (c) name (d) Hello, name!
6. 6.⚡ Which tag holds JavaScript in a page? (a) <js> (b) <style> (c) <code> (d) <script>
7. 7.⚡ What does this code show?
   let name = "Kabir";
   console.log("Hi, " + name + "!"); (a) name (b) Hi, Kabir! (c) Kabir (d) Hi, name!
8. 8.⚡ What does this code show?
   let name = "Kabir";
   console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) Welcome, Kabir! (c) name (d) Kabir
9. 9.⚡ What number does this code print?
   let coins = 9;
   coins = coins + 20;
   coins = coins - 9;
   console.log(coins);
10. 10.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 7;
    console.log(x + y); (a) Error (b) 9 (c) 27
11. 11.⚡ Which JavaScript word runs code when true? (a) console.log() (b) if (c) for (d) alert()
12. 12.⚡ Which word makes a new variable? (a) give (b) make (c) put (d) let
13. 13.⚡ What does this code show?
    let name = "Meera";
    alert("Welcome, " + name + "!"); (a) Welcome, Meera! (b) name (c) Welcome, name! (d) Meera
14. 14.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 7;
    console.log(x + y); (a) Error (b) 47 (c) 11
15. 15.⚡ What does alert() show? (a) a table (b) a picture (c) a new tab (d) a pop-up box
16. 16.⚡ What does JavaScript add to a web page? (a) actions and changes (b) the domain name (c) the page title (d) only colours
17. 17.⚡ What number does this code print?
    let a = 25;
    let b = 4;
    console.log(a + b);
18. 18.⚡ A JavaScript file usually ends with which extension? (a) .jpg (b) .js (c) .css (d) .html
19. 19.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 2;
    console.log(x + y); (a) Error (b) 11 (c) 92
20. 20.⚡ What number does this code print?
    let a = 18;
    let b = 7;
    console.log(a + b);
21. 21.⚡ What number does this code print?
    let score = 7;
    score = score + 13;
    score = score - 15;
    console.log(score);
22. 22.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 2;
    console.log(x + y); (a) 52 (b) Error (c) 7
23. 23.⚡ 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
24. 24.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 6;
    console.log(x + y); (a) 8 (b) 26 (c) Error
25. 25.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 1;
    console.log(x + y); (a) Error (b) 8 (c) 71
26. 26.⚡ What number does this code print?
    let coins = 10;
    coins = coins + 2;
    coins = coins - 8;
    console.log(coins);
27. 27.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 2;
    console.log(x + y); (a) Error (b) 32 (c) 5
28. 28.⚡ Which JavaScript word writes in the console? (a) if (b) alert() (c) console.log() (d) let
29. 29.⚡ What number does this code print?
    let books = 24;
    books = books + 10;
    books = books - 5;
    console.log(books);
30. 30.⚡ What number does this code print?
    let score = 10;
    score = score + 10;
    score = score - 10;
    console.log(score);
31. 31.⚡ What number does this code print?
    let apples = 9;
    apples = apples + 12;
    apples = apples - 21;
    console.log(apples);
32. 32.⚡ Which JavaScript word makes a new variable? (a) console.log() (b) for (c) alert() (d) let
33. 33.⚡ What number does this code print?
    let a = 6;
    let b = 10;
    console.log(a * b);
34. 34.⚡ What number does this code print?
    let runs = 10;
    runs = runs + 13;
    runs = runs - 14;
    console.log(runs);
35. 35.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 5;
    console.log(x + y); (a) Error (b) 10 (c) 55
36. 36.⚡ What number does this code print?
    let a = 25;
    let b = 21;
    console.log(a - b);
37. 37.⚡ What number does this code print?
    let a = 34;
    let b = 40;
    console.log(a + b);
38. 38.⚡ What number does this code print?
    let a = 44;
    let b = 30;
    console.log(a - b);
39. 39.⚡ What does this code show?
    let name = "Meera";
    console.log("Hello, " + name + "!"); (a) Hello, Meera! (b) name (c) Meera (d) Hello, name!
40. 40.⚡ Where does console.log() show its output? (a) on the printer (b) on the title bar (c) in the address bar (d) in the console

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