JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 602 · 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) if (b) let (c) for (d) alert()
2. 2.⚡ What does this code print? (Look at the quotes!)
   let x = "5";
   let y = 8;
   console.log(x + y); (a) Error (b) 13 (c) 58
3. 3.⚡ What does this code print? (Look at the quotes!)
   let x = "3";
   let y = 7;
   console.log(x + y); (a) 10 (b) Error (c) 37
4. 4.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .js (c) .css (d) .jpg
5. 5.⚡ What does this code print? (Look at the quotes!)
   let x = "6";
   let y = 6;
   console.log(x + y); (a) 12 (b) Error (c) 66
6. 6.⚡ What number does this code print?
   let books = 10;
   books = books + 19;
   books = books - 7;
   console.log(books);
7. 7.⚡ What does this code print? (Look at the quotes!)
   let x = "1";
   let y = 9;
   console.log(x + y); (a) 19 (b) 10 (c) Error
8. 8.⚡ What does alert() show? (a) a pop-up box (b) a new tab (c) a picture (d) a table
9. 9.⚡ Which word makes a new variable? (a) give (b) put (c) let (d) make
10. 10.⚡ Which tag holds JavaScript in a page? (a) <js> (b) <script> (c) <code> (d) <style>
11. 11.⚡ What number does this code print?
    let runs = 7;
    runs = runs + 4;
    runs = runs - 7;
    console.log(runs);
12. 12.⚡ Which JavaScript word repeats code? (a) alert() (b) console.log() (c) let (d) for
13. 13.⚡ What does this code show?
    let name = "Aman";
    console.log("Welcome, " + name + "!"); (a) Aman (b) name (c) Welcome, name! (d) Welcome, Aman!
14. 14.⚡ Which JavaScript word runs code when true? (a) let (b) if (c) alert() (d) console.log()
15. 15.⚡ What number does this code print?
    let apples = 5;
    apples = apples + 19;
    apples = apples - 17;
    console.log(apples);
16. 16.⚡ Where does console.log() show its output? (a) on the printer (b) in the address bar (c) in the console (d) on the title bar
17. 17.⚡ What does this code show?
    let name = "Meera";
    console.log("Hi, " + name + "!"); (a) name (b) Meera (c) Hi, Meera! (d) Hi, name!
18. 18.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 4;
    console.log(x + y); (a) 11 (b) 74 (c) Error
19. 19.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 7;
    console.log(x + y); (a) Error (b) 8 (c) 17
20. 20.⚡ What does this code show?
    let name = "Meera";
    console.log("Hello, " + name + "!"); (a) Hello, Meera! (b) name (c) Hello, name! (d) Meera
21. 21.⚡ What number does this code print?
    let a = 47;
    let b = 10;
    console.log(a + b);
22. 22.⚡ What number does this code print?
    let a = 48;
    let b = 2;
    console.log(a + b);
23. 23.⚡ What number does this code print?
    let marks = 28;
    marks = marks + 4;
    marks = marks - 6;
    console.log(marks);
24. 24.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) for (c) let (d) if
25. 25.⚡ What number does this code print?
    let runs = 9;
    runs = runs + 4;
    runs = runs - 10;
    console.log(runs);
26. 26.⚡ What number does this code print?
    let marks = 12;
    marks = marks + 17;
    marks = marks - 27;
    console.log(marks);
27. 27.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 5;
    console.log(x + y); (a) 65 (b) 11 (c) Error
28. 28.⚡ What number does this code print?
    let books = 20;
    books = books + 4;
    books = books - 13;
    console.log(books);
29. 29.⚡ What number does this code print?
    let a = 44;
    let b = 11;
    console.log(a - b);
30. 30.⚡ What number does this code print?
    let books = 8;
    books = books + 7;
    books = books - 13;
    console.log(books);
31. 31.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 1;
    console.log(x + y); (a) Error (b) 2 (c) 11
32. 32.⚡ What number does this code print?
    let a = 7;
    let b = 2;
    console.log(a * b);
33. 33.⚡ Which JavaScript word writes in the console? (a) if (b) alert() (c) for (d) console.log()
34. 34.⚡ What does this code show?
    let name = "Zoya";
    alert("Hi, " + name + "!"); (a) Hi, Zoya! (b) Zoya (c) name (d) Hi, name!
35. 35.⚡ What number does this code print?
    let books = 22;
    books = books + 8;
    books = books - 7;
    console.log(books);
36. 36.⚡ What number does this code print?
    let a = 13;
    let b = 4;
    console.log(a - b);
37. 37.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 2;
    console.log(x + y); (a) 11 (b) Error (c) 92
38. 38.⚡ What number does this code print?
    let a = 46;
    let b = 34;
    console.log(a + b);
39. 39.⚡ What does this code show?
    let name = "Arjun";
    alert("Hello, " + name + "!"); (a) name (b) Arjun (c) Hello, name! (d) Hello, Arjun!
40. 40.⚡ What number does this code print?
    let books = 10;
    books = books + 3;
    books = books - 9;
    console.log(books);

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