JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 979 · 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.⚡ Which JavaScript word makes a new variable? (a) alert() (b) if (c) let (d) console.log()
2. 2.⚡ What number does this code print?
   let a = 58;
   let b = 28;
   console.log(a - b);
3. 3.⚡ What does this code print? (Look at the quotes!)
   let x = "3";
   let y = 5;
   console.log(x + y); (a) 8 (b) 35 (c) Error
4. 4.⚡ Which word makes a new variable? (a) make (b) give (c) let (d) put
5. 5.⚡ What number does this code print?
   let a = 7;
   let b = 24;
   console.log(a + b);
6. 6.⚡ What number does this code print?
   let runs = 26;
   runs = runs + 3;
   runs = runs - 3;
   console.log(runs);
7. 7.⚡ What does alert() show? (a) a pop-up box (b) a new tab (c) a picture (d) a table
8. 8.⚡ What does this code show?
   let name = "Arjun";
   console.log("Hi, " + name + "!"); (a) Hi, name! (b) Arjun (c) Hi, Arjun! (d) name
9. 9.⚡ Which tag holds JavaScript in a page? (a) <js> (b) <code> (c) <script> (d) <style>
10. 10.⚡ Which JavaScript word runs code when true? (a) alert() (b) if (c) for (d) let
11. 11.⚡ What number does this code print?
    let runs = 18;
    runs = runs + 9;
    runs = runs - 24;
    console.log(runs);
12. 12.⚡ What does this code show?
    let name = "Zoya";
    console.log("Hi, " + name + "!"); (a) Hi, name! (b) name (c) Hi, Zoya! (d) Zoya
13. 13.⚡ A JavaScript file usually ends with which extension? (a) .jpg (b) .html (c) .css (d) .js
14. 14.⚡ What does this code show?
    let name = "Riya";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Hello, Riya! (d) Riya
15. 15.⚡ What number does this code print?
    let coins = 12;
    coins = coins + 2;
    coins = coins - 1;
    console.log(coins);
16. 16.⚡ Which JavaScript word writes in the console? (a) for (b) alert() (c) console.log() (d) let
17. 17.⚡ What number does this code print?
    let a = 15;
    let b = 1;
    console.log(a - b);
18. 18.⚡ What does JavaScript add to a web page? (a) the domain name (b) the page title (c) only colours (d) actions and changes
19. 19.⚡ What number does this code print?
    let a = 39;
    let b = 11;
    console.log(a - b);
20. 20.⚡ What number does this code print?
    let a = 57;
    let b = 12;
    console.log(a - b);
21. 21.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 6;
    console.log(x + y); (a) 86 (b) 14 (c) Error
22. 22.⚡ What does this code show?
    let name = "Kabir";
    console.log("Welcome, " + name + "!"); (a) Welcome, Kabir! (b) name (c) Kabir (d) Welcome, name!
23. 23.⚡ What number does this code print?
    let books = 15;
    books = books + 4;
    books = books - 5;
    console.log(books);
24. 24.⚡ What number does this code print?
    let a = 36;
    let b = 9;
    console.log(a - b);
25. 25.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 7;
    console.log(x + y); (a) 12 (b) 57 (c) Error
26. 26.⚡ Which JavaScript word shows a pop-up box? (a) let (b) alert() (c) if (d) for
27. 27.⚡ Which JavaScript word repeats code? (a) if (b) alert() (c) console.log() (d) for
28. 28.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 9;
    console.log(x + y); (a) 10 (b) 19 (c) Error
29. 29.⚡ Where does console.log() show its output? (a) on the title bar (b) in the console (c) in the address bar (d) on the printer
30. 30.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 9;
    console.log(x + y); (a) 89 (b) Error (c) 17
31. 31.⚡ What number does this code print?
    let apples = 15;
    apples = apples + 12;
    apples = apples - 12;
    console.log(apples);
32. 32.⚡ What does this code show?
    let name = "Aman";
    alert("Hi, " + name + "!"); (a) Hi, Aman! (b) Aman (c) Hi, name! (d) name
33. 33.⚡ What number does this code print?
    let a = 57;
    let b = 28;
    console.log(a + b);
34. 34.⚡ What does this code show?
    let name = "Meera";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) Hello, Meera! (c) Meera (d) name
35. 35.⚡ What number does this code print?
    let a = 58;
    let b = 4;
    console.log(a - b);
36. 36.⚡ What number does this code print?
    let score = 8;
    score = score + 2;
    score = score - 7;
    console.log(score);
37. 37.⚡ What does this code show?
    let name = "Arjun";
    alert("Well done, " + name + "!"); (a) Arjun (b) Well done, name! (c) name (d) Well done, Arjun!
38. 38.⚡ What number does this code print?
    let a = 32;
    let b = 20;
    console.log(a + b);
39. 39.⚡ What number does this code print?
    let score = 14;
    score = score + 16;
    score = score - 24;
    console.log(score);
40. 40.⚡ What does this code show?
    let name = "Zoya";
    alert("Hello, " + name + "!"); (a) Hello, Zoya! (b) name (c) Hello, name! (d) Zoya

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