JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 406 · 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 JavaScript add to a web page? (a) actions and changes (b) only colours (c) the page title (d) the domain name
2. 2.⚡ What number does this code print?
   let apples = 5;
   apples = apples + 4;
   apples = apples - 3;
   console.log(apples);
3. 3.⚡ What does this code print? (Look at the quotes!)
   let x = "1";
   let y = 5;
   console.log(x + y); (a) 6 (b) Error (c) 15
4. 4.⚡ What does this code print? (Look at the quotes!)
   let x = "7";
   let y = 5;
   console.log(x + y); (a) 75 (b) 12 (c) Error
5. 5.⚡ What does alert() show? (a) a table (b) a picture (c) a pop-up box (d) a new tab
6. 6.⚡ Which JavaScript word makes a new variable? (a) alert() (b) for (c) let (d) console.log()
7. 7.⚡ What does this code show?
   let name = "Zoya";
   console.log("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Zoya (d) Hello, Zoya!
8. 8.⚡ What number does this code print?
   let a = 9;
   let b = 12;
   console.log(a * b);
9. 9.⚡ What does this code print? (Look at the quotes!)
   let x = "4";
   let y = 4;
   console.log(x + y); (a) Error (b) 44 (c) 8
10. 10.⚡ What number does this code print?
    let marks = 11;
    marks = marks + 8;
    marks = marks - 5;
    console.log(marks);
11. 11.⚡ What number does this code print?
    let a = 48;
    let b = 20;
    console.log(a - b);
12. 12.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 8;
    console.log(x + y); (a) 58 (b) Error (c) 13
13. 13.⚡ What number does this code print?
    let a = 53;
    let b = 37;
    console.log(a - b);
14. 14.⚡ What does this code show?
    let name = "Riya";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) Welcome, Riya! (c) name (d) Riya
15. 15.⚡ What number does this code print?
    let a = 52;
    let b = 7;
    console.log(a - b);
16. 16.⚡ 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
17. 17.⚡ What number does this code print?
    let coins = 5;
    coins = coins + 13;
    coins = coins - 10;
    console.log(coins);
18. 18.⚡ What number does this code print?
    let a = 47;
    let b = 16;
    console.log(a - b);
19. 19.⚡ What number does this code print?
    let a = 36;
    let b = 18;
    console.log(a - b);
20. 20.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <js> (c) <script> (d) <code>
21. 21.⚡ What does this code show?
    let name = "Arjun";
    alert("Well done, " + name + "!"); (a) Arjun (b) Well done, name! (c) Well done, Arjun! (d) name
22. 22.⚡ A JavaScript file usually ends with which extension? (a) .jpg (b) .css (c) .html (d) .js
23. 23.⚡ What number does this code print?
    let a = 2;
    let b = 11;
    console.log(a * b);
24. 24.⚡ What number does this code print?
    let a = 5;
    let b = 39;
    console.log(a + b);
25. 25.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 9;
    console.log(x + y); (a) 69 (b) Error (c) 15
26. 26.⚡ What does this code show?
    let name = "Arjun";
    console.log("Well done, " + name + "!"); (a) Well done, Arjun! (b) Arjun (c) name (d) Well done, name!
27. 27.⚡ What number does this code print?
    let a = 5;
    let b = 7;
    console.log(a * b);
28. 28.⚡ Where does console.log() show its output? (a) in the console (b) on the title bar (c) in the address bar (d) on the printer
29. 29.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 3;
    console.log(x + y); (a) 8 (b) 53 (c) Error
30. 30.⚡ Which JavaScript word repeats code? (a) console.log() (b) if (c) alert() (d) for
31. 31.⚡ Which JavaScript word shows a pop-up box? (a) console.log() (b) alert() (c) if (d) let
32. 32.⚡ What does this code show?
    let name = "Aman";
    console.log("Well done, " + name + "!"); (a) Well done, name! (b) name (c) Well done, Aman! (d) Aman
33. 33.⚡ What does this code show?
    let name = "Kabir";
    alert("Welcome, " + name + "!"); (a) Welcome, name! (b) name (c) Kabir (d) Welcome, Kabir!
34. 34.⚡ What does this code show?
    let name = "Aman";
    alert("Hi, " + name + "!"); (a) Hi, Aman! (b) Aman (c) Hi, name! (d) name
35. 35.⚡ Which word makes a new variable? (a) let (b) give (c) put (d) make
36. 36.⚡ Which JavaScript word runs code when true? (a) for (b) console.log() (c) if (d) alert()
37. 37.⚡ What number does this code print?
    let coins = 19;
    coins = coins + 19;
    coins = coins - 12;
    console.log(coins);
38. 38.⚡ What number does this code print?
    let a = 2;
    let b = 3;
    console.log(a * b);
39. 39.⚡ What number does this code print?
    let a = 7;
    let b = 11;
    console.log(a * b);
40. 40.⚡ 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

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