JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 210 · 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 this code print? (Look at the quotes!)
   let x = "2";
   let y = 2;
   console.log(x + y); (a) 4 (b) 22 (c) Error
2. 2.⚡ What does this code print? (Look at the quotes!)
   let x = "7";
   let y = 3;
   console.log(x + y); (a) 73 (b) 10 (c) Error
3. 3.⚡ Which JavaScript word runs code when true? (a) let (b) alert() (c) if (d) console.log()
4. 4.⚡ What number does this code print?
   let a = 32;
   let b = 8;
   console.log(a - b);
5. 5.⚡ What number does this code print?
   let books = 20;
   books = books + 18;
   books = books - 15;
   console.log(books);
6. 6.⚡ Which JavaScript word makes a new variable? (a) alert() (b) for (c) let (d) console.log()
7. 7.⚡ What does JavaScript add to a web page? (a) the domain name (b) only colours (c) actions and changes (d) the page title
8. 8.⚡ What number does this code print?
   let books = 24;
   books = books + 15;
   books = books - 24;
   console.log(books);
9. 9.⚡ Which JavaScript word shows a pop-up box? (a) for (b) if (c) alert() (d) console.log()
10. 10.⚡ What does alert() show? (a) a table (b) a pop-up box (c) a new tab (d) a picture
11. 11.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 2;
    console.log(x + y); (a) Error (b) 12 (c) 3
12. 12.⚡ What does this code show?
    let name = "Riya";
    alert("Well done, " + name + "!"); (a) Riya (b) Well done, Riya! (c) Well done, name! (d) name
13. 13.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 1;
    console.log(x + y); (a) 9 (b) Error (c) 81
14. 14.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 2;
    console.log(x + y); (a) 5 (b) Error (c) 32
15. 15.⚡ Which JavaScript word writes in the console? (a) for (b) if (c) let (d) console.log()
16. 16.⚡ Which tag holds JavaScript in a page? (a) <script> (b) <style> (c) <code> (d) <js>
17. 17.⚡ What does this code show?
    let name = "Arjun";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) Hello, Arjun! (c) Arjun (d) name
18. 18.⚡ What does this code show?
    let name = "Meera";
    console.log("Welcome, " + name + "!"); (a) name (b) Welcome, Meera! (c) Welcome, name! (d) Meera
19. 19.⚡ What number does this code print?
    let a = 48;
    let b = 28;
    console.log(a - b);
20. 20.⚡ What number does this code print?
    let runs = 7;
    runs = runs + 18;
    runs = runs - 5;
    console.log(runs);
21. 21.⚡ What number does this code print?
    let a = 32;
    let b = 21;
    console.log(a - b);
22. 22.⚡ What number does this code print?
    let a = 9;
    let b = 3;
    console.log(a * b);
23. 23.⚡ What does this code show?
    let name = "Zoya";
    console.log("Welcome, " + name + "!"); (a) Zoya (b) Welcome, Zoya! (c) name (d) Welcome, name!
24. 24.⚡ What number does this code print?
    let a = 50;
    let b = 16;
    console.log(a + b);
25. 25.⚡ What number does this code print?
    let a = 6;
    let b = 9;
    console.log(a * b);
26. 26.⚡ What does this code show?
    let name = "Aman";
    alert("Welcome, " + name + "!"); (a) Welcome, Aman! (b) Aman (c) Welcome, name! (d) name
27. 27.⚡ Where does console.log() show its output? (a) in the address bar (b) in the console (c) on the title bar (d) on the printer
28. 28.⚡ What does this code show?
    let name = "Zoya";
    console.log("Well done, " + name + "!"); (a) Well done, Zoya! (b) Zoya (c) name (d) Well done, name!
29. 29.⚡ What number does this code print?
    let apples = 28;
    apples = apples + 13;
    apples = apples - 32;
    console.log(apples);
30. 30.⚡ What number does this code print?
    let a = 58;
    let b = 6;
    console.log(a + b);
31. 31.⚡ What number does this code print?
    let a = 8;
    let b = 4;
    console.log(a - b);
32. 32.⚡ What number does this code print?
    let apples = 19;
    apples = apples + 4;
    apples = apples - 2;
    console.log(apples);
33. 33.⚡ What number does this code print?
    let books = 7;
    books = books + 5;
    books = books - 10;
    console.log(books);
34. 34.⚡ What number does this code print?
    let a = 46;
    let b = 15;
    console.log(a + b);
35. 35.⚡ What does this code show?
    let name = "Aman";
    alert("Hello, " + name + "!"); (a) Hello, Aman! (b) Aman (c) Hello, name! (d) name
36. 36.⚡ What does this code show?
    let name = "Arjun";
    alert("Hi, " + name + "!"); (a) Hi, name! (b) name (c) Hi, Arjun! (d) Arjun
37. 37.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 4;
    console.log(x + y); (a) 34 (b) 7 (c) Error
38. 38.⚡ What number does this code print?
    let apples = 21;
    apples = apples + 8;
    apples = apples - 23;
    console.log(apples);
39. 39.⚡ What does this code show?
    let name = "Aman";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) name (c) Aman (d) Welcome, Aman!
40. 40.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 3;
    console.log(x + y); (a) 33 (b) Error (c) 6

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