JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 746 · 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 number does this code print?
   let a = 34;
   let b = 12;
   console.log(a - b);
2. 2.⚡ What does this code show?
   let name = "Aman";
   alert("Well done, " + name + "!"); (a) Aman (b) Well done, name! (c) name (d) Well done, Aman!
3. 3.⚡ What does alert() show? (a) a picture (b) a table (c) a pop-up box (d) a new tab
4. 4.⚡ What number does this code print?
   let marks = 29;
   marks = marks + 14;
   marks = marks - 21;
   console.log(marks);
5. 5.⚡ What number does this code print?
   let a = 30;
   let b = 2;
   console.log(a - b);
6. 6.⚡ What does this code show?
   let name = "Riya";
   console.log("Well done, " + name + "!"); (a) Well done, Riya! (b) Well done, name! (c) Riya (d) name
7. 7.⚡ What does this code print? (Look at the quotes!)
   let x = "2";
   let y = 5;
   console.log(x + y); (a) 7 (b) 25 (c) Error
8. 8.⚡ Which JavaScript word writes in the console? (a) if (b) console.log() (c) for (d) alert()
9. 9.⚡ What number does this code print?
   let a = 30;
   let b = 8;
   console.log(a + b);
10. 10.⚡ What number does this code print?
    let a = 38;
    let b = 2;
    console.log(a - b);
11. 11.⚡ Which word makes a new variable? (a) make (b) let (c) give (d) put
12. 12.⚡ What number does this code print?
    let a = 23;
    let b = 37;
    console.log(a + b);
13. 13.⚡ Where does console.log() show its output? (a) in the address bar (b) on the printer (c) in the console (d) on the title bar
14. 14.⚡ What number does this code print?
    let a = 60;
    let b = 1;
    console.log(a - b);
15. 15.⚡ What number does this code print?
    let a = 23;
    let b = 27;
    console.log(a + b);
16. 16.⚡ Which JavaScript word runs code when true? (a) if (b) console.log() (c) for (d) alert()
17. 17.⚡ What number does this code print?
    let books = 18;
    books = books + 2;
    books = books - 3;
    console.log(books);
18. 18.⚡ What number does this code print?
    let books = 19;
    books = books + 11;
    books = books - 5;
    console.log(books);
19. 19.⚡ Which JavaScript word makes a new variable? (a) let (b) console.log() (c) alert() (d) if
20. 20.⚡ What number does this code print?
    let a = 3;
    let b = 10;
    console.log(a * b);
21. 21.⚡ A JavaScript file usually ends with which extension? (a) .jpg (b) .css (c) .js (d) .html
22. 22.⚡ What does this code show?
    let name = "Arjun";
    console.log("Welcome, " + name + "!"); (a) Arjun (b) Welcome, Arjun! (c) Welcome, name! (d) name
23. 23.⚡ Which JavaScript word repeats code? (a) alert() (b) console.log() (c) for (d) if
24. 24.⚡ What number does this code print?
    let a = 23;
    let b = 18;
    console.log(a + b);
25. 25.⚡ What number does this code print?
    let a = 12;
    let b = 11;
    console.log(a + b);
26. 26.⚡ 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
27. 27.⚡ What number does this code print?
    let a = 49;
    let b = 11;
    console.log(a + b);
28. 28.⚡ What does JavaScript add to a web page? (a) the page title (b) only colours (c) actions and changes (d) the domain name
29. 29.⚡ What number does this code print?
    let a = 5;
    let b = 9;
    console.log(a * b);
30. 30.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 7;
    console.log(x + y); (a) 15 (b) 87 (c) Error
31. 31.⚡ What number does this code print?
    let apples = 6;
    apples = apples + 15;
    apples = apples - 4;
    console.log(apples);
32. 32.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <code> (c) <script> (d) <js>
33. 33.⚡ What number does this code print?
    let a = 15;
    let b = 12;
    console.log(a - b);
34. 34.⚡ What does this code show?
    let name = "Aman";
    console.log("Hi, " + name + "!"); (a) Hi, Aman! (b) name (c) Hi, name! (d) Aman
35. 35.⚡ What number does this code print?
    let a = 8;
    let b = 6;
    console.log(a - b);
36. 36.⚡ What number does this code print?
    let score = 18;
    score = score + 13;
    score = score - 23;
    console.log(score);
37. 37.⚡ What number does this code print?
    let a = 13;
    let b = 25;
    console.log(a + b);
38. 38.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 2;
    console.log(x + y); (a) 72 (b) 9 (c) Error
39. 39.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 7;
    console.log(x + y); (a) 37 (b) Error (c) 10
40. 40.⚡ What number does this code print?
    let apples = 26;
    apples = apples + 17;
    apples = apples - 27;
    console.log(apples);

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