JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 618 · 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 = 42;
   let b = 18;
   console.log(a + b);
2. 2.⚡ What does alert() show? (a) a table (b) a new tab (c) a pop-up box (d) a picture
3. 3.⚡ What does this code show?
   let name = "Arjun";
   alert("Hi, " + name + "!"); (a) Arjun (b) name (c) Hi, Arjun! (d) Hi, name!
4. 4.⚡ What number does this code print?
   let books = 10;
   books = books + 17;
   books = books - 1;
   console.log(books);
5. 5.⚡ What does this code show?
   let name = "Riya";
   alert("Hello, " + name + "!"); (a) Hello, Riya! (b) Hello, name! (c) name (d) Riya
6. 6.⚡ 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
7. 7.⚡ What does this code show?
   let name = "Meera";
   console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) Meera (c) Welcome, Meera! (d) name
8. 8.⚡ What does JavaScript add to a web page? (a) actions and changes (b) the domain name (c) only colours (d) the page title
9. 9.⚡ What does this code show?
   let name = "Meera";
   alert("Hello, " + name + "!"); (a) Hello, name! (b) Meera (c) name (d) Hello, Meera!
10. 10.⚡ What does this code show?
    let name = "Arjun";
    console.log("Hi, " + name + "!"); (a) name (b) Hi, name! (c) Arjun (d) Hi, Arjun!
11. 11.⚡ Which JavaScript word repeats code? (a) let (b) alert() (c) for (d) console.log()
12. 12.⚡ Which word makes a new variable? (a) let (b) put (c) give (d) make
13. 13.⚡ What number does this code print?
    let a = 41;
    let b = 19;
    console.log(a + b);
14. 14.⚡ What number does this code print?
    let a = 41;
    let b = 39;
    console.log(a - b);
15. 15.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <script> (c) <js> (d) <code>
16. 16.⚡ What does this code show?
    let name = "Kabir";
    alert("Welcome, " + name + "!"); (a) Kabir (b) name (c) Welcome, Kabir! (d) Welcome, name!
17. 17.⚡ Which JavaScript word writes in the console? (a) for (b) alert() (c) console.log() (d) if
18. 18.⚡ What number does this code print?
    let a = 4;
    let b = 4;
    console.log(a * b);
19. 19.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 6;
    console.log(x + y); (a) 11 (b) Error (c) 56
20. 20.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 4;
    console.log(x + y); (a) 24 (b) 6 (c) Error
21. 21.⚡ What number does this code print?
    let runs = 8;
    runs = runs + 6;
    runs = runs - 3;
    console.log(runs);
22. 22.⚡ What number does this code print?
    let runs = 20;
    runs = runs + 19;
    runs = runs - 18;
    console.log(runs);
23. 23.⚡ Which JavaScript word runs code when true? (a) let (b) if (c) alert() (d) console.log()
24. 24.⚡ What does this code show?
    let name = "Riya";
    console.log("Hi, " + name + "!"); (a) name (b) Riya (c) Hi, Riya! (d) Hi, name!
25. 25.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 2;
    console.log(x + y); (a) 4 (b) 22 (c) Error
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 5;
    console.log(x + y); (a) 85 (b) 13 (c) Error
27. 27.⚡ What number does this code print?
    let a = 44;
    let b = 38;
    console.log(a + b);
28. 28.⚡ What number does this code print?
    let a = 11;
    let b = 4;
    console.log(a * b);
29. 29.⚡ What number does this code print?
    let runs = 13;
    runs = runs + 11;
    runs = runs - 6;
    console.log(runs);
30. 30.⚡ What number does this code print?
    let a = 9;
    let b = 5;
    console.log(a * b);
31. 31.⚡ 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
32. 32.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 5;
    console.log(x + y); (a) Error (b) 7 (c) 25
33. 33.⚡ What number does this code print?
    let books = 16;
    books = books + 18;
    books = books - 31;
    console.log(books);
34. 34.⚡ What number does this code print?
    let a = 23;
    let b = 5;
    console.log(a - b);
35. 35.⚡ What number does this code print?
    let a = 52;
    let b = 34;
    console.log(a + b);
36. 36.⚡ What number does this code print?
    let a = 27;
    let b = 33;
    console.log(a + b);
37. 37.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 3;
    console.log(x + y); (a) 7 (b) Error (c) 43
38. 38.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 1;
    console.log(x + y); (a) 10 (b) 91 (c) Error
39. 39.⚡ What number does this code print?
    let a = 12;
    let b = 13;
    console.log(a + b);
40. 40.⚡ What number does this code print?
    let marks = 16;
    marks = marks + 19;
    marks = marks - 25;
    console.log(marks);

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