JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 430 · 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 = 3;
   console.log(x + y); (a) Error (b) 23 (c) 5
2. 2.⚡ Which JavaScript word runs code when true? (a) console.log() (b) for (c) if (d) alert()
3. 3.⚡ What number does this code print?
   let marks = 21;
   marks = marks + 17;
   marks = marks - 34;
   console.log(marks);
4. 4.⚡ Which word makes a new variable? (a) let (b) put (c) give (d) make
5. 5.⚡ Which JavaScript word shows a pop-up box? (a) if (b) for (c) alert() (d) console.log()
6. 6.⚡ Which JavaScript word repeats code? (a) if (b) let (c) alert() (d) for
7. 7.⚡ Which JavaScript word makes a new variable? (a) for (b) let (c) alert() (d) console.log()
8. 8.⚡ What does this code show?
   let name = "Zoya";
   console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) name (c) Zoya (d) Welcome, Zoya!
9. 9.⚡ What number does this code print?
   let marks = 12;
   marks = marks + 5;
   marks = marks - 10;
   console.log(marks);
10. 10.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 8;
    console.log(x + y); (a) 18 (b) Error (c) 9
11. 11.⚡ Which JavaScript word writes in the console? (a) for (b) if (c) console.log() (d) let
12. 12.⚡ What does this code show?
    let name = "Riya";
    alert("Hi, " + name + "!"); (a) Riya (b) name (c) Hi, name! (d) Hi, Riya!
13. 13.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hello, " + name + "!"); (a) Kabir (b) Hello, Kabir! (c) Hello, name! (d) name
14. 14.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 1;
    console.log(x + y); (a) Error (b) 4 (c) 31
15. 15.⚡ What number does this code print?
    let coins = 19;
    coins = coins + 18;
    coins = coins - 11;
    console.log(coins);
16. 16.⚡ What does this code show?
    let name = "Riya";
    console.log("Well done, " + name + "!"); (a) name (b) Well done, name! (c) Riya (d) Well done, Riya!
17. 17.⚡ Where does console.log() show its output? (a) on the title bar (b) in the console (c) on the printer (d) in the address bar
18. 18.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 6;
    console.log(x + y); (a) 26 (b) 8 (c) Error
19. 19.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 3;
    console.log(x + y); (a) Error (b) 6 (c) 33
20. 20.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 4;
    console.log(x + y); (a) Error (b) 24 (c) 6
21. 21.⚡ What number does this code print?
    let a = 3;
    let b = 2;
    console.log(a * b);
22. 22.⚡ What does this code show?
    let name = "Aman";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) Aman (c) name (d) Hello, Aman!
23. 23.⚡ What number does this code print?
    let a = 10;
    let b = 8;
    console.log(a * b);
24. 24.⚡ What number does this code print?
    let a = 6;
    let b = 6;
    console.log(a * b);
25. 25.⚡ What does JavaScript add to a web page? (a) actions and changes (b) the page title (c) the domain name (d) only colours
26. 26.⚡ What number does this code print?
    let a = 12;
    let b = 4;
    console.log(a - b);
27. 27.⚡ What number does this code print?
    let a = 22;
    let b = 21;
    console.log(a - b);
28. 28.⚡ What number does this code print?
    let runs = 12;
    runs = runs + 7;
    runs = runs - 9;
    console.log(runs);
29. 29.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <code> (c) <js> (d) <script>
30. 30.⚡ What does alert() show? (a) a picture (b) a pop-up box (c) a new tab (d) a table
31. 31.⚡ What number does this code print?
    let books = 15;
    books = books + 4;
    books = books - 12;
    console.log(books);
32. 32.⚡ What number does this code print?
    let a = 2;
    let b = 9;
    console.log(a * b);
33. 33.⚡ What does this code show?
    let name = "Aman";
    console.log("Welcome, " + name + "!"); (a) name (b) Welcome, name! (c) Welcome, Aman! (d) Aman
34. 34.⚡ What number does this code print?
    let apples = 13;
    apples = apples + 10;
    apples = apples - 23;
    console.log(apples);
35. 35.⚡ What number does this code print?
    let apples = 6;
    apples = apples + 18;
    apples = apples - 17;
    console.log(apples);
36. 36.⚡ What does this code show?
    let name = "Arjun";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) Arjun (c) name (d) Hello, Arjun!
37. 37.⚡ What number does this code print?
    let a = 53;
    let b = 10;
    console.log(a + b);
38. 38.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 4;
    console.log(x + y); (a) 64 (b) 10 (c) Error
39. 39.⚡ What number does this code print?
    let books = 14;
    books = books + 19;
    books = books - 18;
    console.log(books);
40. 40.⚡ What number does this code print?
    let runs = 27;
    runs = runs + 2;
    runs = runs - 13;
    console.log(runs);

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