JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 505 · 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) only colours (b) actions and changes (c) the page title (d) the domain name
2. 2.⚡ Which JavaScript word repeats code? (a) if (b) alert() (c) for (d) let
3. 3.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .jpg (c) .html (d) .js
4. 4.⚡ What number does this code print?
   let a = 36;
   let b = 5;
   console.log(a + b);
5. 5.⚡ What number does this code print?
   let a = 6;
   let b = 12;
   console.log(a * b);
6. 6.⚡ What does this code print? (Look at the quotes!)
   let x = "3";
   let y = 1;
   console.log(x + y); (a) 31 (b) Error (c) 4
7. 7.⚡ What does this code print? (Look at the quotes!)
   let x = "8";
   let y = 3;
   console.log(x + y); (a) 11 (b) 83 (c) Error
8. 8.⚡ Which word makes a new variable? (a) make (b) put (c) let (d) give
9. 9.⚡ What does alert() show? (a) a picture (b) a table (c) a pop-up box (d) a new tab
10. 10.⚡ Which JavaScript word runs code when true? (a) alert() (b) console.log() (c) if (d) let
11. 11.⚡ Which JavaScript word shows a pop-up box? (a) for (b) console.log() (c) alert() (d) let
12. 12.⚡ What does this code show?
    let name = "Aman";
    console.log("Welcome, " + name + "!"); (a) name (b) Aman (c) Welcome, name! (d) Welcome, Aman!
13. 13.⚡ What does this code show?
    let name = "Kabir";
    alert("Hello, " + name + "!"); (a) name (b) Hello, name! (c) Hello, Kabir! (d) Kabir
14. 14.⚡ What does this code show?
    let name = "Kabir";
    console.log("Well done, " + name + "!"); (a) name (b) Well done, Kabir! (c) Kabir (d) Well done, name!
15. 15.⚡ What number does this code print?
    let score = 13;
    score = score + 20;
    score = score - 7;
    console.log(score);
16. 16.⚡ Where does console.log() show its output? (a) on the title bar (b) in the address bar (c) on the printer (d) in the console
17. 17.⚡ What number does this code print?
    let a = 11;
    let b = 37;
    console.log(a + b);
18. 18.⚡ Which JavaScript word makes a new variable? (a) for (b) alert() (c) let (d) console.log()
19. 19.⚡ What does this code show?
    let name = "Riya";
    alert("Welcome, " + name + "!"); (a) Riya (b) Welcome, Riya! (c) name (d) Welcome, name!
20. 20.⚡ What does this code show?
    let name = "Riya";
    console.log("Hi, " + name + "!"); (a) name (b) Riya (c) Hi, name! (d) Hi, Riya!
21. 21.⚡ What does this code show?
    let name = "Riya";
    alert("Well done, " + name + "!"); (a) name (b) Riya (c) Well done, Riya! (d) Well done, name!
22. 22.⚡ What number does this code print?
    let score = 19;
    score = score + 2;
    score = score - 19;
    console.log(score);
23. 23.⚡ What does this code show?
    let name = "Meera";
    alert("Hi, " + name + "!"); (a) name (b) Hi, name! (c) Hi, Meera! (d) Meera
24. 24.⚡ What does this code show?
    let name = "Aman";
    console.log("Hello, " + name + "!"); (a) name (b) Hello, name! (c) Hello, Aman! (d) Aman
25. 25.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 4;
    console.log(x + y); (a) Error (b) 11 (c) 74
26. 26.⚡ Which JavaScript word writes in the console? (a) if (b) for (c) console.log() (d) alert()
27. 27.⚡ Which tag holds JavaScript in a page? (a) <script> (b) <style> (c) <js> (d) <code>
28. 28.⚡ What does this code show?
    let name = "Aman";
    alert("Welcome, " + name + "!"); (a) Welcome, Aman! (b) name (c) Aman (d) Welcome, name!
29. 29.⚡ What does this code show?
    let name = "Aman";
    alert("Hi, " + name + "!"); (a) name (b) Aman (c) Hi, name! (d) Hi, Aman!
30. 30.⚡ 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
31. 31.⚡ What number does this code print?
    let a = 52;
    let b = 21;
    console.log(a + b);
32. 32.⚡ What does this code show?
    let name = "Riya";
    console.log("Hello, " + name + "!"); (a) name (b) Hello, name! (c) Hello, Riya! (d) Riya
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 5;
    console.log(x + y); (a) 12 (b) Error (c) 75
34. 34.⚡ What number does this code print?
    let a = 40;
    let b = 33;
    console.log(a + b);
35. 35.⚡ What number does this code print?
    let a = 8;
    let b = 11;
    console.log(a * b);
36. 36.⚡ What number does this code print?
    let apples = 5;
    apples = apples + 16;
    apples = apples - 9;
    console.log(apples);
37. 37.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hi, " + name + "!"); (a) Kabir (b) Hi, name! (c) Hi, Kabir! (d) name
38. 38.⚡ What number does this code print?
    let marks = 19;
    marks = marks + 19;
    marks = marks - 8;
    console.log(marks);
39. 39.⚡ What number does this code print?
    let apples = 7;
    apples = apples + 18;
    apples = apples - 10;
    console.log(apples);
40. 40.⚡ What number does this code print?
    let a = 9;
    let b = 4;
    console.log(a + b);

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