JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 184 · 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 alert() show? (a) a picture (b) a pop-up box (c) a table (d) a new tab
2. 2.⚡ What number does this code print?
   let a = 12;
   let b = 12;
   console.log(a * b);
3. 3.⚡ Which JavaScript word runs code when true? (a) alert() (b) console.log() (c) if (d) for
4. 4.⚡ What does this code show?
   let name = "Meera";
   alert("Welcome, " + name + "!"); (a) name (b) Welcome, Meera! (c) Meera (d) Welcome, name!
5. 5.⚡ 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
6. 6.⚡ What does this code show?
   let name = "Aman";
   alert("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Hello, Aman! (d) Aman
7. 7.⚡ What number does this code print?
   let score = 11;
   score = score + 11;
   score = score - 1;
   console.log(score);
8. 8.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .jpg (c) .css (d) .html
9. 9.⚡ What does this code show?
   let name = "Arjun";
   console.log("Hi, " + name + "!"); (a) Hi, name! (b) Arjun (c) Hi, Arjun! (d) name
10. 10.⚡ What number does this code print?
    let a = 2;
    let b = 11;
    console.log(a * b);
11. 11.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 1;
    console.log(x + y); (a) Error (b) 3 (c) 21
12. 12.⚡ What does this code show?
    let name = "Meera";
    console.log("Welcome, " + name + "!"); (a) Meera (b) Welcome, Meera! (c) name (d) Welcome, name!
13. 13.⚡ Which JavaScript word repeats code? (a) alert() (b) for (c) let (d) console.log()
14. 14.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 6;
    console.log(x + y); (a) 13 (b) Error (c) 76
15. 15.⚡ What number does this code print?
    let a = 2;
    let b = 7;
    console.log(a * b);
16. 16.⚡ What number does this code print?
    let score = 7;
    score = score + 2;
    score = score - 5;
    console.log(score);
17. 17.⚡ What does this code show?
    let name = "Riya";
    alert("Welcome, " + name + "!"); (a) name (b) Riya (c) Welcome, name! (d) Welcome, Riya!
18. 18.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 7;
    console.log(x + y); (a) 9 (b) Error (c) 27
19. 19.⚡ What number does this code print?
    let score = 29;
    score = score + 7;
    score = score - 9;
    console.log(score);
20. 20.⚡ What does this code show?
    let name = "Meera";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) Hello, Meera! (c) name (d) Meera
21. 21.⚡ What number does this code print?
    let a = 9;
    let b = 35;
    console.log(a + b);
22. 22.⚡ What number does this code print?
    let a = 20;
    let b = 12;
    console.log(a - b);
23. 23.⚡ Which JavaScript word makes a new variable? (a) let (b) if (c) console.log() (d) for
24. 24.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 3;
    console.log(x + y); (a) 23 (b) Error (c) 5
25. 25.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 5;
    console.log(x + y); (a) 9 (b) 45 (c) Error
26. 26.⚡ What number does this code print?
    let a = 9;
    let b = 16;
    console.log(a + b);
27. 27.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) Hello, Kabir! (c) name (d) Kabir
28. 28.⚡ What number does this code print?
    let a = 19;
    let b = 31;
    console.log(a + b);
29. 29.⚡ What number does this code print?
    let runs = 15;
    runs = runs + 15;
    runs = runs - 18;
    console.log(runs);
30. 30.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 9;
    console.log(x + y); (a) Error (b) 14 (c) 59
31. 31.⚡ What does this code show?
    let name = "Riya";
    alert("Hello, " + name + "!"); (a) Riya (b) Hello, name! (c) name (d) Hello, Riya!
32. 32.⚡ Where does console.log() show its output? (a) on the title bar (b) in the address bar (c) on the printer (d) in the console
33. 33.⚡ What number does this code print?
    let apples = 17;
    apples = apples + 5;
    apples = apples - 19;
    console.log(apples);
34. 34.⚡ What number does this code print?
    let a = 8;
    let b = 9;
    console.log(a * b);
35. 35.⚡ Which word makes a new variable? (a) give (b) put (c) make (d) let
36. 36.⚡ What number does this code print?
    let a = 30;
    let b = 25;
    console.log(a + b);
37. 37.⚡ Which tag holds JavaScript in a page? (a) <js> (b) <style> (c) <script> (d) <code>
38. 38.⚡ What number does this code print?
    let a = 9;
    let b = 12;
    console.log(a * b);
39. 39.⚡ What number does this code print?
    let books = 12;
    books = books + 20;
    books = books - 20;
    console.log(books);
40. 40.⚡ What number does this code print?
    let a = 35;
    let b = 16;
    console.log(a - b);

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