JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 872 · 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 does this code print? (Look at the quotes!)
   let x = "2";
   let y = 1;
   console.log(x + y); (a) Error (b) 21 (c) 3
2. 2.⚡ Which JavaScript word writes in the console? (a) let (b) if (c) alert() (d) console.log()
3. 3.⚡ Which word makes a new variable? (a) put (b) let (c) make (d) give
4. 4.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) if (c) let (d) console.log()
5. 5.⚡ 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
6. 6.⚡ Which JavaScript word makes a new variable? (a) if (b) let (c) for (d) alert()
7. 7.⚡ What number does this code print?
   let a = 42;
   let b = 1;
   console.log(a + b);
8. 8.⚡ What number does this code print?
   let a = 29;
   let b = 23;
   console.log(a - b);
9. 9.⚡ Which JavaScript word repeats code? (a) for (b) let (c) alert() (d) console.log()
10. 10.⚡ What number does this code print?
    let books = 28;
    books = books + 20;
    books = books - 47;
    console.log(books);
11. 11.⚡ A JavaScript file usually ends with which extension? (a) .jpg (b) .css (c) .html (d) .js
12. 12.⚡ What number does this code print?
    let coins = 20;
    coins = coins + 3;
    coins = coins - 1;
    console.log(coins);
13. 13.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 1;
    console.log(x + y); (a) 11 (b) 2 (c) Error
14. 14.⚡ What number does this code print?
    let coins = 12;
    coins = coins + 19;
    coins = coins - 26;
    console.log(coins);
15. 15.⚡ Which tag holds JavaScript in a page? (a) <script> (b) <code> (c) <js> (d) <style>
16. 16.⚡ What number does this code print?
    let a = 41;
    let b = 26;
    console.log(a + b);
17. 17.⚡ What number does this code print?
    let a = 25;
    let b = 8;
    console.log(a + b);
18. 18.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 6;
    console.log(x + y); (a) 46 (b) 10 (c) Error
19. 19.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 5;
    console.log(x + y); (a) 85 (b) Error (c) 13
20. 20.⚡ What number does this code print?
    let a = 5;
    let b = 3;
    console.log(a * b);
21. 21.⚡ What number does this code print?
    let a = 55;
    let b = 39;
    console.log(a - b);
22. 22.⚡ What number does this code print?
    let runs = 21;
    runs = runs + 12;
    runs = runs - 25;
    console.log(runs);
23. 23.⚡ What does this code show?
    let name = "Meera";
    alert("Well done, " + name + "!"); (a) name (b) Well done, name! (c) Well done, Meera! (d) Meera
24. 24.⚡ What does this code show?
    let name = "Arjun";
    alert("Welcome, " + name + "!"); (a) Arjun (b) Welcome, name! (c) Welcome, Arjun! (d) name
25. 25.⚡ What number does this code print?
    let a = 7;
    let b = 4;
    console.log(a * b);
26. 26.⚡ What does this code show?
    let name = "Aman";
    alert("Hello, " + name + "!"); (a) Aman (b) Hello, Aman! (c) Hello, name! (d) name
27. 27.⚡ What does alert() show? (a) a new tab (b) a pop-up box (c) a table (d) a picture
28. 28.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 8;
    console.log(x + y); (a) Error (b) 28 (c) 10
29. 29.⚡ 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
30. 30.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 1;
    console.log(x + y); (a) 81 (b) Error (c) 9
31. 31.⚡ What number does this code print?
    let a = 35;
    let b = 33;
    console.log(a + b);
32. 32.⚡ What does this code show?
    let name = "Meera";
    console.log("Hello, " + name + "!"); (a) Meera (b) name (c) Hello, Meera! (d) Hello, name!
33. 33.⚡ Where does console.log() show its output? (a) in the address bar (b) in the console (c) on the printer (d) on the title bar
34. 34.⚡ What number does this code print?
    let score = 29;
    score = score + 9;
    score = score - 37;
    console.log(score);
35. 35.⚡ What does this code show?
    let name = "Zoya";
    console.log("Hello, " + name + "!"); (a) name (b) Hello, Zoya! (c) Hello, name! (d) Zoya
36. 36.⚡ What number does this code print?
    let books = 28;
    books = books + 6;
    books = books - 21;
    console.log(books);
37. 37.⚡ What does this code show?
    let name = "Kabir";
    alert("Welcome, " + name + "!"); (a) Kabir (b) name (c) Welcome, Kabir! (d) Welcome, name!
38. 38.⚡ What number does this code print?
    let marks = 9;
    marks = marks + 3;
    marks = marks - 5;
    console.log(marks);
39. 39.⚡ What number does this code print?
    let books = 8;
    books = books + 8;
    books = books - 8;
    console.log(books);
40. 40.⚡ What number does this code print?
    let books = 10;
    books = books + 2;
    books = books - 9;
    console.log(books);

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