JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 542 · 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.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .js (c) .css (d) .jpg
2. 2.⚡ What does this code print? (Look at the quotes!)
   let x = "5";
   let y = 8;
   console.log(x + y); (a) 13 (b) Error (c) 58
3. 3.⚡ What does this code show?
   let name = "Kabir";
   console.log("Hi, " + name + "!"); (a) Kabir (b) Hi, name! (c) name (d) Hi, Kabir!
4. 4.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) console.log() (c) for (d) if
5. 5.⚡ What number does this code print?
   let marks = 14;
   marks = marks + 8;
   marks = marks - 6;
   console.log(marks);
6. 6.⚡ Which JavaScript word repeats code? (a) console.log() (b) for (c) alert() (d) let
7. 7.⚡ Which word makes a new variable? (a) make (b) give (c) put (d) let
8. 8.⚡ What does JavaScript add to a web page? (a) the domain name (b) only colours (c) actions and changes (d) the page title
9. 9.⚡ Which JavaScript word makes a new variable? (a) alert() (b) console.log() (c) let (d) if
10. 10.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 1;
    console.log(x + y); (a) Error (b) 91 (c) 10
11. 11.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 5;
    console.log(x + y); (a) Error (b) 65 (c) 11
12. 12.⚡ Which JavaScript word writes in the console? (a) console.log() (b) for (c) if (d) let
13. 13.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 4;
    console.log(x + y); (a) 13 (b) Error (c) 94
14. 14.⚡ What does this code show?
    let name = "Aman";
    alert("Hi, " + name + "!"); (a) Aman (b) Hi, name! (c) Hi, Aman! (d) name
15. 15.⚡ Where does console.log() show its output? (a) in the console (b) in the address bar (c) on the printer (d) on the title bar
16. 16.⚡ What does this code show?
    let name = "Arjun";
    alert("Well done, " + name + "!"); (a) name (b) Well done, Arjun! (c) Arjun (d) Well done, name!
17. 17.⚡ Which JavaScript word runs code when true? (a) if (b) alert() (c) for (d) let
18. 18.⚡ What number does this code print?
    let a = 38;
    let b = 27;
    console.log(a + b);
19. 19.⚡ Which tag holds JavaScript in a page? (a) <js> (b) <code> (c) <style> (d) <script>
20. 20.⚡ What does this code show?
    let name = "Arjun";
    alert("Hello, " + name + "!"); (a) Hello, Arjun! (b) Hello, name! (c) name (d) Arjun
21. 21.⚡ What does this code show?
    let name = "Arjun";
    alert("Hi, " + name + "!"); (a) Hi, name! (b) Hi, Arjun! (c) name (d) Arjun
22. 22.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 5;
    console.log(x + y); (a) Error (b) 7 (c) 25
23. 23.⚡ What number does this code print?
    let a = 6;
    let b = 8;
    console.log(a * b);
24. 24.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) Kabir (c) name (d) Hello, Kabir!
25. 25.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 2;
    console.log(x + y); (a) Error (b) 32 (c) 5
26. 26.⚡ What does alert() show? (a) a picture (b) a new tab (c) a table (d) a pop-up box
27. 27.⚡ What number does this code print?
    let a = 32;
    let b = 17;
    console.log(a - b);
28. 28.⚡ What number does this code print?
    let a = 48;
    let b = 31;
    console.log(a + b);
29. 29.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 3;
    console.log(x + y); (a) 5 (b) Error (c) 23
30. 30.⚡ What number does this code print?
    let a = 37;
    let b = 7;
    console.log(a + b);
31. 31.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 3;
    console.log(x + y); (a) 33 (b) Error (c) 6
32. 32.⚡ What number does this code print?
    let a = 10;
    let b = 5;
    console.log(a * b);
33. 33.⚡ 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
34. 34.⚡ What number does this code print?
    let coins = 12;
    coins = coins + 6;
    coins = coins - 9;
    console.log(coins);
35. 35.⚡ What does this code show?
    let name = "Meera";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Hello, Meera! (d) Meera
36. 36.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 4;
    console.log(x + y); (a) Error (b) 24 (c) 6
37. 37.⚡ What number does this code print?
    let apples = 6;
    apples = apples + 20;
    apples = apples - 17;
    console.log(apples);
38. 38.⚡ What does this code show?
    let name = "Riya";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) name (c) Welcome, Riya! (d) Riya
39. 39.⚡ What number does this code print?
    let coins = 16;
    coins = coins + 10;
    coins = coins - 20;
    console.log(coins);
40. 40.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 4;
    console.log(x + y); (a) 9 (b) Error (c) 54

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