JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 960 · 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 shows a pop-up box? (a) if (b) console.log() (c) let (d) alert()
2. 2.⚡ What number does this code print?
   let a = 25;
   let b = 1;
   console.log(a - b);
3. 3.⚡ What does this code show?
   let name = "Meera";
   alert("Welcome, " + name + "!"); (a) Meera (b) Welcome, Meera! (c) name (d) Welcome, name!
4. 4.⚡ What number does this code print?
   let marks = 30;
   marks = marks + 19;
   marks = marks - 18;
   console.log(marks);
5. 5.⚡ What number does this code print?
   let score = 25;
   score = score + 9;
   score = score - 16;
   console.log(score);
6. 6.⚡ Which JavaScript word writes in the console? (a) console.log() (b) let (c) alert() (d) if
7. 7.⚡ Which tag holds JavaScript in a page? (a) <script> (b) <style> (c) <code> (d) <js>
8. 8.⚡ What does alert() show? (a) a table (b) a new tab (c) a picture (d) a pop-up box
9. 9.⚡ What does this code print? (Look at the quotes!)
   let x = "1";
   let y = 4;
   console.log(x + y); (a) 14 (b) Error (c) 5
10. 10.⚡ What number does this code print?
    let score = 18;
    score = score + 10;
    score = score - 4;
    console.log(score);
11. 11.⚡ What number does this code print?
    let a = 7;
    let b = 16;
    console.log(a + b);
12. 12.⚡ Which word makes a new variable? (a) put (b) let (c) give (d) make
13. 13.⚡ What does JavaScript add to a web page? (a) the page title (b) only colours (c) actions and changes (d) the domain name
14. 14.⚡ What number does this code print?
    let a = 38;
    let b = 28;
    console.log(a - b);
15. 15.⚡ A JavaScript file usually ends with which extension? (a) .jpg (b) .js (c) .css (d) .html
16. 16.⚡ What number does this code print?
    let books = 10;
    books = books + 7;
    books = books - 6;
    console.log(books);
17. 17.⚡ What number does this code print?
    let apples = 26;
    apples = apples + 3;
    apples = apples - 6;
    console.log(apples);
18. 18.⚡ Which JavaScript word runs code when true? (a) if (b) let (c) console.log() (d) alert()
19. 19.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 5;
    console.log(x + y); (a) 9 (b) Error (c) 45
20. 20.⚡ Where does console.log() show its output? (a) on the title bar (b) on the printer (c) in the console (d) in the address bar
21. 21.⚡ What does this code show?
    let name = "Meera";
    console.log("Hi, " + name + "!"); (a) Meera (b) Hi, Meera! (c) Hi, name! (d) name
22. 22.⚡ What number does this code print?
    let a = 38;
    let b = 16;
    console.log(a - b);
23. 23.⚡ What number does this code print?
    let score = 8;
    score = score + 9;
    score = score - 5;
    console.log(score);
24. 24.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 6;
    console.log(x + y); (a) 10 (b) 46 (c) Error
25. 25.⚡ What does this code show?
    let name = "Meera";
    alert("Hello, " + name + "!"); (a) Hello, Meera! (b) Hello, name! (c) name (d) Meera
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 9;
    console.log(x + y); (a) 15 (b) Error (c) 69
27. 27.⚡ What does this code show?
    let name = "Arjun";
    console.log("Well done, " + name + "!"); (a) name (b) Arjun (c) Well done, Arjun! (d) Well done, name!
28. 28.⚡ Which JavaScript word makes a new variable? (a) alert() (b) if (c) console.log() (d) let
29. 29.⚡ Which JavaScript word repeats code? (a) if (b) for (c) let (d) console.log()
30. 30.⚡ What number does this code print?
    let a = 17;
    let b = 7;
    console.log(a - b);
31. 31.⚡ What number does this code print?
    let a = 7;
    let b = 4;
    console.log(a * b);
32. 32.⚡ What number does this code print?
    let a = 39;
    let b = 11;
    console.log(a + b);
33. 33.⚡ What number does this code print?
    let a = 15;
    let b = 1;
    console.log(a - b);
34. 34.⚡ What does this code show?
    let name = "Meera";
    console.log("Welcome, " + name + "!"); (a) name (b) Meera (c) Welcome, Meera! (d) Welcome, name!
35. 35.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 5;
    console.log(x + y); (a) 7 (b) Error (c) 25
36. 36.⚡ What number does this code print?
    let runs = 6;
    runs = runs + 12;
    runs = runs - 11;
    console.log(runs);
37. 37.⚡ What number does this code print?
    let a = 4;
    let b = 6;
    console.log(a * b);
38. 38.⚡ What number does this code print?
    let coins = 10;
    coins = coins + 10;
    coins = coins - 18;
    console.log(coins);
39. 39.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 5;
    console.log(x + y); (a) 12 (b) 75 (c) Error
40. 40.⚡ What does this code show?
    let name = "Aman";
    console.log("Hello, " + name + "!"); (a) Hello, Aman! (b) name (c) Hello, name! (d) Aman

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