JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 342 · 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.⚡ Which JavaScript word runs code when true? (a) let (b) console.log() (c) for (d) if
2. 2.⚡ Which JavaScript word repeats code? (a) alert() (b) if (c) for (d) console.log()
3. 3.⚡ What does this code print? (Look at the quotes!)
   let x = "5";
   let y = 2;
   console.log(x + y); (a) 7 (b) Error (c) 52
4. 4.⚡ What number does this code print?
   let a = 12;
   let b = 4;
   console.log(a - b);
5. 5.⚡ What does this code print? (Look at the quotes!)
   let x = "3";
   let y = 4;
   console.log(x + y); (a) Error (b) 34 (c) 7
6. 6.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .jpg (c) .css (d) .html
7. 7.⚡ Which JavaScript word makes a new variable? (a) console.log() (b) for (c) if (d) let
8. 8.⚡ Which JavaScript word writes in the console? (a) alert() (b) if (c) console.log() (d) let
9. 9.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <js> (c) <style> (d) <script>
10. 10.⚡ What number does this code print?
    let a = 30;
    let b = 36;
    console.log(a + b);
11. 11.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) let (c) if (d) console.log()
12. 12.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 1;
    console.log(x + y); (a) 2 (b) 11 (c) Error
13. 13.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 4;
    console.log(x + y); (a) 94 (b) 13 (c) Error
14. 14.⚡ What number does this code print?
    let coins = 25;
    coins = coins + 18;
    coins = coins - 3;
    console.log(coins);
15. 15.⚡ What does this code show?
    let name = "Arjun";
    alert("Well done, " + name + "!"); (a) Well done, Arjun! (b) Arjun (c) Well done, name! (d) name
16. 16.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 3;
    console.log(x + y); (a) 12 (b) Error (c) 93
17. 17.⚡ What number does this code print?
    let a = 38;
    let b = 6;
    console.log(a - b);
18. 18.⚡ What number does this code print?
    let a = 53;
    let b = 9;
    console.log(a - b);
19. 19.⚡ What number does this code print?
    let marks = 7;
    marks = marks + 9;
    marks = marks - 16;
    console.log(marks);
20. 20.⚡ What number does this code print?
    let a = 8;
    let b = 11;
    console.log(a * b);
21. 21.⚡ What number does this code print?
    let a = 20;
    let b = 32;
    console.log(a + b);
22. 22.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 9;
    console.log(x + y); (a) 11 (b) 29 (c) Error
23. 23.⚡ What number does this code print?
    let a = 19;
    let b = 17;
    console.log(a - b);
24. 24.⚡ What number does this code print?
    let marks = 30;
    marks = marks + 5;
    marks = marks - 5;
    console.log(marks);
25. 25.⚡ What does this code show?
    let name = "Zoya";
    alert("Well done, " + name + "!"); (a) Zoya (b) Well done, name! (c) name (d) Well done, Zoya!
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 2;
    console.log(x + y); (a) Error (b) 62 (c) 8
27. 27.⚡ What does alert() show? (a) a new tab (b) a table (c) a pop-up box (d) a picture
28. 28.⚡ What number does this code print?
    let marks = 19;
    marks = marks + 16;
    marks = marks - 11;
    console.log(marks);
29. 29.⚡ What number does this code print?
    let a = 43;
    let b = 12;
    console.log(a + b);
30. 30.⚡ What number does this code print?
    let a = 31;
    let b = 3;
    console.log(a + b);
31. 31.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 3;
    console.log(x + y); (a) Error (b) 10 (c) 73
32. 32.⚡ What number does this code print?
    let a = 50;
    let b = 8;
    console.log(a + b);
33. 33.⚡ Where does console.log() show its output? (a) on the printer (b) on the title bar (c) in the address bar (d) in the console
34. 34.⚡ What does this code show?
    let name = "Meera";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Hello, Meera! (d) Meera
35. 35.⚡ What number does this code print?
    let a = 10;
    let b = 3;
    console.log(a * b);
36. 36.⚡ What number does this code print?
    let a = 12;
    let b = 7;
    console.log(a * b);
37. 37.⚡ What number does this code print?
    let a = 11;
    let b = 9;
    console.log(a * b);
38. 38.⚡ What does this code show?
    let name = "Aman";
    console.log("Welcome, " + name + "!"); (a) Aman (b) name (c) Welcome, Aman! (d) Welcome, name!
39. 39.⚡ What does JavaScript add to a web page? (a) only colours (b) the domain name (c) actions and changes (d) the page title
40. 40.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hi, " + name + "!"); (a) Kabir (b) Hi, name! (c) name (d) Hi, Kabir!

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