JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 169 · 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 new tab (c) a pop-up box (d) a table
2. 2.⚡ What number does this code print?
   let runs = 11;
   runs = runs + 15;
   runs = runs - 1;
   console.log(runs);
3. 3.⚡ Which word makes a new variable? (a) put (b) make (c) give (d) let
4. 4.⚡ What number does this code print?
   let a = 33;
   let b = 21;
   console.log(a - b);
5. 5.⚡ What number does this code print?
   let a = 8;
   let b = 8;
   console.log(a * b);
6. 6.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .jpg (c) .js (d) .html
7. 7.⚡ What does this code print? (Look at the quotes!)
   let x = "6";
   let y = 2;
   console.log(x + y); (a) 8 (b) Error (c) 62
8. 8.⚡ Which JavaScript word writes in the console? (a) alert() (b) if (c) console.log() (d) let
9. 9.⚡ What does this code show?
   let name = "Meera";
   alert("Welcome, " + name + "!"); (a) name (b) Meera (c) Welcome, Meera! (d) Welcome, name!
10. 10.⚡ What does this code show?
    let name = "Riya";
    console.log("Hello, " + name + "!"); (a) name (b) Hello, Riya! (c) Riya (d) Hello, name!
11. 11.⚡ Which JavaScript word shows a pop-up box? (a) if (b) let (c) alert() (d) for
12. 12.⚡ Which tag holds JavaScript in a page? (a) <js> (b) <style> (c) <script> (d) <code>
13. 13.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 1;
    console.log(x + y); (a) 21 (b) 3 (c) Error
14. 14.⚡ What number does this code print?
    let apples = 20;
    apples = apples + 10;
    apples = apples - 8;
    console.log(apples);
15. 15.⚡ Where does console.log() show its output? (a) on the title bar (b) on the printer (c) in the address bar (d) in the console
16. 16.⚡ What number does this code print?
    let marks = 19;
    marks = marks + 6;
    marks = marks - 11;
    console.log(marks);
17. 17.⚡ What number does this code print?
    let a = 6;
    let b = 12;
    console.log(a * b);
18. 18.⚡ What number does this code print?
    let runs = 18;
    runs = runs + 8;
    runs = runs - 12;
    console.log(runs);
19. 19.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 1;
    console.log(x + y); (a) Error (b) 61 (c) 7
20. 20.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 4;
    console.log(x + y); (a) 5 (b) Error (c) 14
21. 21.⚡ What does this code show?
    let name = "Aman";
    console.log("Well done, " + name + "!"); (a) Well done, Aman! (b) Well done, name! (c) name (d) Aman
22. 22.⚡ Which JavaScript word repeats code? (a) let (b) alert() (c) for (d) console.log()
23. 23.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 4;
    console.log(x + y); (a) 44 (b) Error (c) 8
24. 24.⚡ What does this code show?
    let name = "Aman";
    alert("Welcome, " + name + "!"); (a) name (b) Welcome, name! (c) Welcome, Aman! (d) Aman
25. 25.⚡ Which JavaScript word runs code when true? (a) if (b) alert() (c) console.log() (d) for
26. 26.⚡ What number does this code print?
    let a = 28;
    let b = 27;
    console.log(a + b);
27. 27.⚡ 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
28. 28.⚡ What does this code show?
    let name = "Meera";
    console.log("Hello, " + name + "!"); (a) Hello, Meera! (b) Hello, name! (c) Meera (d) name
29. 29.⚡ Which JavaScript word makes a new variable? (a) for (b) alert() (c) let (d) if
30. 30.⚡ What does this code show?
    let name = "Riya";
    alert("Hi, " + name + "!"); (a) name (b) Riya (c) Hi, name! (d) Hi, Riya!
31. 31.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 3;
    console.log(x + y); (a) 6 (b) 33 (c) Error
32. 32.⚡ What number does this code print?
    let books = 5;
    books = books + 9;
    books = books - 14;
    console.log(books);
33. 33.⚡ What does this code show?
    let name = "Aman";
    console.log("Welcome, " + name + "!"); (a) name (b) Welcome, name! (c) Welcome, Aman! (d) Aman
34. 34.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 7;
    console.log(x + y); (a) 57 (b) Error (c) 12
35. 35.⚡ What number does this code print?
    let marks = 5;
    marks = marks + 18;
    marks = marks - 2;
    console.log(marks);
36. 36.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 5;
    console.log(x + y); (a) Error (b) 10 (c) 55
37. 37.⚡ What does this code show?
    let name = "Riya";
    alert("Welcome, " + name + "!"); (a) Welcome, Riya! (b) Riya (c) Welcome, name! (d) name
38. 38.⚡ What number does this code print?
    let a = 38;
    let b = 32;
    console.log(a + b);
39. 39.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 6;
    console.log(x + y); (a) 7 (b) Error (c) 16
40. 40.⚡ What does this code show?
    let name = "Arjun";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) Arjun (c) name (d) Hello, Arjun!

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