JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 843 · 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 = 23;
   books = books + 12;
   books = books - 11;
   console.log(books);
2. 2.⚡ What does this code print? (Look at the quotes!)
   let x = "7";
   let y = 9;
   console.log(x + y); (a) 16 (b) Error (c) 79
3. 3.⚡ What does this code show?
   let name = "Zoya";
   console.log("Hello, " + name + "!"); (a) Zoya (b) Hello, name! (c) name (d) Hello, Zoya!
4. 4.⚡ What number does this code print?
   let a = 59;
   let b = 16;
   console.log(a - b);
5. 5.⚡ What does this code print? (Look at the quotes!)
   let x = "2";
   let y = 7;
   console.log(x + y); (a) Error (b) 27 (c) 9
6. 6.⚡ What number does this code print?
   let coins = 15;
   coins = coins + 2;
   coins = coins - 16;
   console.log(coins);
7. 7.⚡ What number does this code print?
   let a = 8;
   let b = 18;
   console.log(a + b);
8. 8.⚡ What does this code show?
   let name = "Aman";
   console.log("Well done, " + name + "!"); (a) name (b) Well done, name! (c) Aman (d) Well done, Aman!
9. 9.⚡ What does this code print? (Look at the quotes!)
   let x = "5";
   let y = 4;
   console.log(x + y); (a) 54 (b) Error (c) 9
10. 10.⚡ Where does console.log() show its output? (a) in the console (b) on the title bar (c) on the printer (d) in the address bar
11. 11.⚡ Which JavaScript word makes a new variable? (a) if (b) let (c) console.log() (d) for
12. 12.⚡ What does this code show?
    let name = "Zoya";
    alert("Hi, " + name + "!"); (a) Zoya (b) name (c) Hi, Zoya! (d) Hi, name!
13. 13.⚡ Which word makes a new variable? (a) let (b) put (c) make (d) give
14. 14.⚡ What number does this code print?
    let a = 4;
    let b = 4;
    console.log(a * b);
15. 15.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 5;
    console.log(x + y); (a) 45 (b) 9 (c) Error
16. 16.⚡ Which tag holds JavaScript in a page? (a) <script> (b) <js> (c) <code> (d) <style>
17. 17.⚡ Which JavaScript word shows a pop-up box? (a) for (b) let (c) alert() (d) if
18. 18.⚡ What does this code show?
    let name = "Arjun";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) Hello, Arjun! (c) name (d) Arjun
19. 19.⚡ What does this code show?
    let name = "Riya";
    alert("Well done, " + name + "!"); (a) name (b) Well done, Riya! (c) Riya (d) Well done, name!
20. 20.⚡ What number does this code print?
    let coins = 19;
    coins = coins + 19;
    coins = coins - 22;
    console.log(coins);
21. 21.⚡ What number does this code print?
    let runs = 15;
    runs = runs + 5;
    runs = runs - 8;
    console.log(runs);
22. 22.⚡ What does JavaScript add to a web page? (a) the domain name (b) only colours (c) actions and changes (d) the page title
23. 23.⚡ What does alert() show? (a) a picture (b) a pop-up box (c) a new tab (d) a table
24. 24.⚡ A JavaScript file usually ends with which extension? (a) .jpg (b) .html (c) .js (d) .css
25. 25.⚡ What number does this code print?
    let a = 19;
    let b = 14;
    console.log(a - b);
26. 26.⚡ Which JavaScript word repeats code? (a) let (b) if (c) for (d) console.log()
27. 27.⚡ What number does this code print?
    let a = 12;
    let b = 6;
    console.log(a * b);
28. 28.⚡ Which JavaScript word writes in the console? (a) let (b) console.log() (c) for (d) if
29. 29.⚡ What number does this code print?
    let marks = 13;
    marks = marks + 9;
    marks = marks - 14;
    console.log(marks);
30. 30.⚡ What does this code show?
    let name = "Aman";
    alert("Hi, " + name + "!"); (a) Hi, name! (b) Aman (c) name (d) Hi, Aman!
31. 31.⚡ What number does this code print?
    let coins = 26;
    coins = coins + 9;
    coins = coins - 24;
    console.log(coins);
32. 32.⚡ What number does this code print?
    let runs = 21;
    runs = runs + 10;
    runs = runs - 30;
    console.log(runs);
33. 33.⚡ What number does this code print?
    let a = 47;
    let b = 37;
    console.log(a - b);
34. 34.⚡ Which JavaScript word runs code when true? (a) let (b) console.log() (c) alert() (d) if
35. 35.⚡ What number does this code print?
    let a = 2;
    let b = 4;
    console.log(a * b);
36. 36.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 3;
    console.log(x + y); (a) 4 (b) Error (c) 13
37. 37.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 2;
    console.log(x + y); (a) 9 (b) Error (c) 72
38. 38.⚡ What number does this code print?
    let a = 5;
    let b = 5;
    console.log(a * b);
39. 39.⚡ What number does this code print?
    let a = 6;
    let b = 8;
    console.log(a * b);
40. 40.⚡ What number does this code print?
    let apples = 11;
    apples = apples + 18;
    apples = apples - 12;
    console.log(apples);

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