JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 126 · 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 = "1";
   let y = 4;
   console.log(x + y); (a) 14 (b) Error (c) 5
2. 2.⚡ What does this code show?
   let name = "Aman";
   console.log("Hello, " + name + "!"); (a) Hello, name! (b) Hello, Aman! (c) name (d) Aman
3. 3.⚡ What number does this code print?
   let apples = 19;
   apples = apples + 4;
   apples = apples - 9;
   console.log(apples);
4. 4.⚡ Which JavaScript word runs code when true? (a) let (b) alert() (c) if (d) console.log()
5. 5.⚡ Which JavaScript word makes a new variable? (a) let (b) console.log() (c) for (d) if
6. 6.⚡ What number does this code print?
   let a = 31;
   let b = 6;
   console.log(a + b);
7. 7.⚡ What does alert() show? (a) a picture (b) a table (c) a pop-up box (d) a new tab
8. 8.⚡ Where does console.log() show its output? (a) in the address bar (b) on the title bar (c) in the console (d) on the printer
9. 9.⚡ Which JavaScript word repeats code? (a) let (b) if (c) for (d) alert()
10. 10.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .jpg (c) .css (d) .js
11. 11.⚡ Which word makes a new variable? (a) let (b) put (c) make (d) give
12. 12.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <js> (c) <script> (d) <code>
13. 13.⚡ What number does this code print?
    let a = 5;
    let b = 14;
    console.log(a + b);
14. 14.⚡ What number does this code print?
    let a = 6;
    let b = 7;
    console.log(a * b);
15. 15.⚡ 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
16. 16.⚡ What does this code show?
    let name = "Meera";
    console.log("Hello, " + name + "!"); (a) Hello, Meera! (b) name (c) Hello, name! (d) Meera
17. 17.⚡ What number does this code print?
    let apples = 13;
    apples = apples + 7;
    apples = apples - 8;
    console.log(apples);
18. 18.⚡ What number does this code print?
    let apples = 25;
    apples = apples + 16;
    apples = apples - 37;
    console.log(apples);
19. 19.⚡ What number does this code print?
    let books = 11;
    books = books + 4;
    books = books - 3;
    console.log(books);
20. 20.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 1;
    console.log(x + y); (a) Error (b) 6 (c) 51
21. 21.⚡ What does this code show?
    let name = "Aman";
    console.log("Well done, " + name + "!"); (a) name (b) Aman (c) Well done, Aman! (d) Well done, name!
22. 22.⚡ What number does this code print?
    let score = 12;
    score = score + 11;
    score = score - 12;
    console.log(score);
23. 23.⚡ What number does this code print?
    let a = 34;
    let b = 18;
    console.log(a - b);
24. 24.⚡ What number does this code print?
    let books = 9;
    books = books + 4;
    books = books - 10;
    console.log(books);
25. 25.⚡ What number does this code print?
    let a = 35;
    let b = 8;
    console.log(a + b);
26. 26.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) console.log() (c) if (d) let
27. 27.⚡ Which JavaScript word writes in the console? (a) alert() (b) for (c) let (d) console.log()
28. 28.⚡ What does this code show?
    let name = "Riya";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) Riya (c) Hello, Riya! (d) name
29. 29.⚡ What does this code show?
    let name = "Meera";
    console.log("Welcome, " + name + "!"); (a) Meera (b) name (c) Welcome, name! (d) Welcome, Meera!
30. 30.⚡ What does this code show?
    let name = "Aman";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) Aman (c) name (d) Hello, Aman!
31. 31.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 6;
    console.log(x + y); (a) Error (b) 11 (c) 56
32. 32.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 5;
    console.log(x + y); (a) Error (b) 8 (c) 35
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 3;
    console.log(x + y); (a) 13 (b) Error (c) 4
34. 34.⚡ What number does this code print?
    let a = 18;
    let b = 22;
    console.log(a + b);
35. 35.⚡ What does this code show?
    let name = "Aman";
    alert("Welcome, " + name + "!"); (a) Welcome, Aman! (b) Aman (c) name (d) Welcome, name!
36. 36.⚡ What number does this code print?
    let score = 11;
    score = score + 7;
    score = score - 5;
    console.log(score);
37. 37.⚡ What number does this code print?
    let a = 26;
    let b = 18;
    console.log(a - b);
38. 38.⚡ What does this code show?
    let name = "Arjun";
    console.log("Hi, " + name + "!"); (a) name (b) Arjun (c) Hi, Arjun! (d) Hi, name!
39. 39.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 9;
    console.log(x + y); (a) 12 (b) 39 (c) Error
40. 40.⚡ What does this code show?
    let name = "Meera";
    alert("Hi, " + name + "!"); (a) name (b) Meera (c) Hi, name! (d) Hi, Meera!

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