JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 524 · 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 = "3";
   let y = 5;
   console.log(x + y); (a) Error (b) 35 (c) 8
2. 2.⚡ What does alert() show? (a) a picture (b) a table (c) a new tab (d) a pop-up box
3. 3.⚡ What number does this code print?
   let a = 12;
   let b = 4;
   console.log(a * b);
4. 4.⚡ What does this code print? (Look at the quotes!)
   let x = "5";
   let y = 4;
   console.log(x + y); (a) Error (b) 9 (c) 54
5. 5.⚡ Which JavaScript word repeats code? (a) if (b) alert() (c) for (d) let
6. 6.⚡ Which JavaScript word shows a pop-up box? (a) for (b) if (c) alert() (d) let
7. 7.⚡ What number does this code print?
   let a = 8;
   let b = 24;
   console.log(a + b);
8. 8.⚡ What does this code print? (Look at the quotes!)
   let x = "3";
   let y = 9;
   console.log(x + y); (a) 39 (b) Error (c) 12
9. 9.⚡ What number does this code print?
   let a = 6;
   let b = 7;
   console.log(a * b);
10. 10.⚡ What number does this code print?
    let a = 16;
    let b = 9;
    console.log(a - b);
11. 11.⚡ What number does this code print?
    let a = 6;
    let b = 12;
    console.log(a * b);
12. 12.⚡ What number does this code print?
    let a = 41;
    let b = 1;
    console.log(a - b);
13. 13.⚡ What does this code show?
    let name = "Aman";
    console.log("Welcome, " + name + "!"); (a) Welcome, Aman! (b) name (c) Aman (d) Welcome, name!
14. 14.⚡ Where does console.log() show its output? (a) in the console (b) on the title bar (c) on the printer (d) in the address bar
15. 15.⚡ What number does this code print?
    let a = 23;
    let b = 20;
    console.log(a + b);
16. 16.⚡ What number does this code print?
    let a = 10;
    let b = 6;
    console.log(a * b);
17. 17.⚡ What number does this code print?
    let score = 29;
    score = score + 3;
    score = score - 12;
    console.log(score);
18. 18.⚡ Which tag holds JavaScript in a page? (a) <js> (b) <script> (c) <style> (d) <code>
19. 19.⚡ What number does this code print?
    let a = 15;
    let b = 25;
    console.log(a + b);
20. 20.⚡ What number does this code print?
    let a = 23;
    let b = 10;
    console.log(a + b);
21. 21.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 8;
    console.log(x + y); (a) Error (b) 88 (c) 16
22. 22.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 5;
    console.log(x + y); (a) Error (b) 14 (c) 95
23. 23.⚡ What number does this code print?
    let score = 22;
    score = score + 19;
    score = score - 20;
    console.log(score);
24. 24.⚡ What number does this code print?
    let coins = 21;
    coins = coins + 6;
    coins = coins - 25;
    console.log(coins);
25. 25.⚡ What does this code show?
    let name = "Meera";
    alert("Well done, " + name + "!"); (a) name (b) Meera (c) Well done, Meera! (d) Well done, name!
26. 26.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hi, " + name + "!"); (a) Hi, Kabir! (b) name (c) Hi, name! (d) Kabir
27. 27.⚡ What does JavaScript add to a web page? (a) the page title (b) only colours (c) actions and changes (d) the domain name
28. 28.⚡ What number does this code print?
    let a = 19;
    let b = 22;
    console.log(a + b);
29. 29.⚡ Which JavaScript word runs code when true? (a) let (b) alert() (c) if (d) for
30. 30.⚡ What number does this code print?
    let a = 17;
    let b = 1;
    console.log(a - b);
31. 31.⚡ What number does this code print?
    let score = 28;
    score = score + 2;
    score = score - 24;
    console.log(score);
32. 32.⚡ 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
33. 33.⚡ What does this code show?
    let name = "Riya";
    alert("Hello, " + name + "!"); (a) Riya (b) Hello, name! (c) Hello, Riya! (d) name
34. 34.⚡ What number does this code print?
    let marks = 14;
    marks = marks + 11;
    marks = marks - 3;
    console.log(marks);
35. 35.⚡ What does this code show?
    let name = "Kabir";
    alert("Hello, " + name + "!"); (a) Kabir (b) Hello, name! (c) Hello, Kabir! (d) name
36. 36.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 7;
    console.log(x + y); (a) 14 (b) 77 (c) Error
37. 37.⚡ Which JavaScript word makes a new variable? (a) console.log() (b) let (c) if (d) for
38. 38.⚡ What number does this code print?
    let a = 3;
    let b = 8;
    console.log(a * b);
39. 39.⚡ What number does this code print?
    let a = 8;
    let b = 3;
    console.log(a * b);
40. 40.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 4;
    console.log(x + y); (a) Error (b) 64 (c) 10

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