JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 585 · 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 table (d) a pop-up box
2. 2.⚡ What does this code show?
   let name = "Kabir";
   alert("Welcome, " + name + "!"); (a) Welcome, Kabir! (b) Kabir (c) Welcome, name! (d) name
3. 3.⚡ What number does this code print?
   let a = 60;
   let b = 23;
   console.log(a - b);
4. 4.⚡ What does this code show?
   let name = "Aman";
   console.log("Well done, " + name + "!"); (a) Well done, name! (b) name (c) Aman (d) Well done, Aman!
5. 5.⚡ What number does this code print?
   let score = 9;
   score = score + 2;
   score = score - 5;
   console.log(score);
6. 6.⚡ What does this code print? (Look at the quotes!)
   let x = "6";
   let y = 3;
   console.log(x + y); (a) 63 (b) Error (c) 9
7. 7.⚡ What does this code print? (Look at the quotes!)
   let x = "4";
   let y = 2;
   console.log(x + y); (a) Error (b) 6 (c) 42
8. 8.⚡ What does this code show?
   let name = "Arjun";
   console.log("Hi, " + name + "!"); (a) name (b) Hi, name! (c) Hi, Arjun! (d) Arjun
9. 9.⚡ What number does this code print?
   let marks = 18;
   marks = marks + 17;
   marks = marks - 12;
   console.log(marks);
10. 10.⚡ What number does this code print?
    let a = 3;
    let b = 2;
    console.log(a * b);
11. 11.⚡ What number does this code print?
    let a = 23;
    let b = 7;
    console.log(a - b);
12. 12.⚡ What number does this code print?
    let coins = 12;
    coins = coins + 6;
    coins = coins - 9;
    console.log(coins);
13. 13.⚡ What does JavaScript add to a web page? (a) the page title (b) only colours (c) actions and changes (d) the domain name
14. 14.⚡ What does this code show?
    let name = "Arjun";
    console.log("Well done, " + name + "!"); (a) name (b) Well done, name! (c) Well done, Arjun! (d) Arjun
15. 15.⚡ What number does this code print?
    let a = 22;
    let b = 6;
    console.log(a - b);
16. 16.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 7;
    console.log(x + y); (a) 13 (b) Error (c) 67
17. 17.⚡ Where does console.log() show its output? (a) in the address bar (b) in the console (c) on the printer (d) on the title bar
18. 18.⚡ What does this code show?
    let name = "Kabir";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) Kabir (c) name (d) Hello, Kabir!
19. 19.⚡ Which JavaScript word writes in the console? (a) let (b) console.log() (c) if (d) alert()
20. 20.⚡ What number does this code print?
    let a = 37;
    let b = 8;
    console.log(a - b);
21. 21.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <code> (c) <js> (d) <script>
22. 22.⚡ What number does this code print?
    let apples = 15;
    apples = apples + 8;
    apples = apples - 3;
    console.log(apples);
23. 23.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 4;
    console.log(x + y); (a) 64 (b) 10 (c) Error
24. 24.⚡ Which JavaScript word runs code when true? (a) if (b) let (c) for (d) alert()
25. 25.⚡ Which word makes a new variable? (a) put (b) let (c) make (d) give
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 4;
    console.log(x + y); (a) Error (b) 7 (c) 34
27. 27.⚡ Which JavaScript word makes a new variable? (a) if (b) alert() (c) console.log() (d) let
28. 28.⚡ What number does this code print?
    let a = 11;
    let b = 4;
    console.log(a * b);
29. 29.⚡ What number does this code print?
    let a = 10;
    let b = 12;
    console.log(a * b);
30. 30.⚡ Which JavaScript word shows a pop-up box? (a) for (b) let (c) console.log() (d) alert()
31. 31.⚡ What does this code show?
    let name = "Kabir";
    console.log("Welcome, " + name + "!"); (a) name (b) Welcome, name! (c) Welcome, Kabir! (d) Kabir
32. 32.⚡ What number does this code print?
    let a = 55;
    let b = 34;
    console.log(a + b);
33. 33.⚡ Which JavaScript word repeats code? (a) for (b) alert() (c) console.log() (d) if
34. 34.⚡ What number does this code print?
    let a = 31;
    let b = 17;
    console.log(a + b);
35. 35.⚡ What number does this code print?
    let a = 49;
    let b = 12;
    console.log(a + b);
36. 36.⚡ What number does this code print?
    let a = 49;
    let b = 3;
    console.log(a + b);
37. 37.⚡ What does this code show?
    let name = "Riya";
    alert("Hi, " + name + "!"); (a) name (b) Hi, name! (c) Hi, Riya! (d) Riya
38. 38.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 9;
    console.log(x + y); (a) 89 (b) 17 (c) Error
39. 39.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 9;
    console.log(x + y); (a) 11 (b) Error (c) 29
40. 40.⚡ What does this code show?
    let name = "Aman";
    alert("Hello, " + name + "!"); (a) name (b) Hello, name! (c) Aman (d) Hello, Aman!

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