JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 281 · 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.⚡ Which JavaScript word makes a new variable? (a) alert() (b) console.log() (c) if (d) let
2. 2.⚡ What does this code print? (Look at the quotes!)
   let x = "9";
   let y = 9;
   console.log(x + y); (a) Error (b) 18 (c) 99
3. 3.⚡ What number does this code print?
   let a = 57;
   let b = 13;
   console.log(a - b);
4. 4.⚡ What does this code show?
   let name = "Zoya";
   console.log("Hello, " + name + "!"); (a) name (b) Zoya (c) Hello, name! (d) Hello, Zoya!
5. 5.⚡ What does this code print? (Look at the quotes!)
   let x = "2";
   let y = 2;
   console.log(x + y); (a) 4 (b) Error (c) 22
6. 6.⚡ Which JavaScript word writes in the console? (a) console.log() (b) if (c) for (d) let
7. 7.⚡ Which tag holds JavaScript in a page? (a) <script> (b) <style> (c) <code> (d) <js>
8. 8.⚡ What does this code show?
   let name = "Arjun";
   console.log("Hi, " + name + "!"); (a) Arjun (b) Hi, Arjun! (c) Hi, name! (d) name
9. 9.⚡ What does JavaScript add to a web page? (a) the page title (b) only colours (c) the domain name (d) actions and changes
10. 10.⚡ Which word makes a new variable? (a) let (b) put (c) give (d) make
11. 11.⚡ Where does console.log() show its output? (a) on the title bar (b) on the printer (c) in the address bar (d) in the console
12. 12.⚡ Which JavaScript word repeats code? (a) if (b) for (c) alert() (d) let
13. 13.⚡ What does this code show?
    let name = "Riya";
    alert("Welcome, " + name + "!"); (a) Welcome, Riya! (b) Riya (c) name (d) Welcome, name!
14. 14.⚡ What number does this code print?
    let a = 35;
    let b = 13;
    console.log(a - b);
15. 15.⚡ What number does this code print?
    let a = 16;
    let b = 32;
    console.log(a + b);
16. 16.⚡ Which JavaScript word shows a pop-up box? (a) for (b) alert() (c) let (d) console.log()
17. 17.⚡ Which JavaScript word runs code when true? (a) alert() (b) for (c) let (d) if
18. 18.⚡ What does this code show?
    let name = "Kabir";
    console.log("Well done, " + name + "!"); (a) Well done, Kabir! (b) name (c) Well done, name! (d) Kabir
19. 19.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 7;
    console.log(x + y); (a) Error (b) 87 (c) 15
20. 20.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 1;
    console.log(x + y); (a) Error (b) 81 (c) 9
21. 21.⚡ What does alert() show? (a) a picture (b) a pop-up box (c) a new tab (d) a table
22. 22.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hi, " + name + "!"); (a) name (b) Kabir (c) Hi, Kabir! (d) Hi, name!
23. 23.⚡ What number does this code print?
    let score = 5;
    score = score + 15;
    score = score - 10;
    console.log(score);
24. 24.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 2;
    console.log(x + y); (a) 92 (b) Error (c) 11
25. 25.⚡ What number does this code print?
    let runs = 14;
    runs = runs + 4;
    runs = runs - 8;
    console.log(runs);
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 2;
    console.log(x + y); (a) 3 (b) Error (c) 12
27. 27.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 3;
    console.log(x + y); (a) 4 (b) Error (c) 13
28. 28.⚡ What number does this code print?
    let books = 16;
    books = books + 7;
    books = books - 15;
    console.log(books);
29. 29.⚡ What number does this code print?
    let a = 12;
    let b = 6;
    console.log(a + b);
30. 30.⚡ What number does this code print?
    let a = 2;
    let b = 4;
    console.log(a * b);
31. 31.⚡ What number does this code print?
    let a = 11;
    let b = 7;
    console.log(a * b);
32. 32.⚡ What number does this code print?
    let marks = 24;
    marks = marks + 16;
    marks = marks - 29;
    console.log(marks);
33. 33.⚡ What number does this code print?
    let a = 27;
    let b = 11;
    console.log(a - b);
34. 34.⚡ What number does this code print?
    let runs = 19;
    runs = runs + 17;
    runs = runs - 18;
    console.log(runs);
35. 35.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 6;
    console.log(x + y); (a) Error (b) 96 (c) 15
36. 36.⚡ What number does this code print?
    let coins = 14;
    coins = coins + 18;
    coins = coins - 6;
    console.log(coins);
37. 37.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 8;
    console.log(x + y); (a) 68 (b) Error (c) 14
38. 38.⚡ What does this code show?
    let name = "Arjun";
    alert("Well done, " + name + "!"); (a) Well done, name! (b) Well done, Arjun! (c) Arjun (d) name
39. 39.⚡ What does this code show?
    let name = "Aman";
    alert("Well done, " + name + "!"); (a) Well done, Aman! (b) name (c) Aman (d) Well done, name!
40. 40.⚡ What number does this code print?
    let books = 20;
    books = books + 7;
    books = books - 4;
    console.log(books);

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