JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 270 · 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 tag holds JavaScript in a page? (a) <code> (b) <style> (c) <js> (d) <script>
2. 2.⚡ What does this code show?
   let name = "Kabir";
   console.log("Hi, " + name + "!"); (a) Hi, name! (b) Kabir (c) Hi, Kabir! (d) name
3. 3.⚡ What number does this code print?
   let marks = 22;
   marks = marks + 10;
   marks = marks - 28;
   console.log(marks);
4. 4.⚡ Which JavaScript word writes in the console? (a) console.log() (b) if (c) let (d) for
5. 5.⚡ What number does this code print?
   let a = 42;
   let b = 14;
   console.log(a - b);
6. 6.⚡ Which JavaScript word repeats code? (a) if (b) console.log() (c) for (d) alert()
7. 7.⚡ What does this code print? (Look at the quotes!)
   let x = "6";
   let y = 2;
   console.log(x + y); (a) 8 (b) Error (c) 62
8. 8.⚡ What does alert() show? (a) a table (b) a pop-up box (c) a new tab (d) a picture
9. 9.⚡ What does JavaScript add to a web page? (a) the domain name (b) only colours (c) the page title (d) actions and changes
10. 10.⚡ Where does console.log() show its output? (a) in the console (b) on the printer (c) on the title bar (d) in the address bar
11. 11.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 3;
    console.log(x + y); (a) 43 (b) Error (c) 7
12. 12.⚡ 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
13. 13.⚡ What does this code show?
    let name = "Riya";
    alert("Welcome, " + name + "!"); (a) Welcome, name! (b) Riya (c) Welcome, Riya! (d) name
14. 14.⚡ Which JavaScript word shows a pop-up box? (a) for (b) alert() (c) console.log() (d) if
15. 15.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 7;
    console.log(x + y); (a) 77 (b) Error (c) 14
16. 16.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .jpg (c) .html (d) .js
17. 17.⚡ What does this code show?
    let name = "Zoya";
    alert("Welcome, " + name + "!"); (a) name (b) Welcome, name! (c) Welcome, Zoya! (d) Zoya
18. 18.⚡ What number does this code print?
    let a = 6;
    let b = 9;
    console.log(a * b);
19. 19.⚡ What number does this code print?
    let books = 15;
    books = books + 8;
    books = books - 8;
    console.log(books);
20. 20.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 2;
    console.log(x + y); (a) 22 (b) Error (c) 4
21. 21.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 8;
    console.log(x + y); (a) 14 (b) 68 (c) Error
22. 22.⚡ What number does this code print?
    let apples = 19;
    apples = apples + 7;
    apples = apples - 7;
    console.log(apples);
23. 23.⚡ What does this code show?
    let name = "Zoya";
    alert("Well done, " + name + "!"); (a) Well done, Zoya! (b) name (c) Well done, name! (d) Zoya
24. 24.⚡ What number does this code print?
    let a = 16;
    let b = 6;
    console.log(a + b);
25. 25.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 5;
    console.log(x + y); (a) 8 (b) Error (c) 35
26. 26.⚡ What does this code show?
    let name = "Arjun";
    alert("Hi, " + name + "!"); (a) Arjun (b) name (c) Hi, name! (d) Hi, Arjun!
27. 27.⚡ Which JavaScript word runs code when true? (a) console.log() (b) if (c) let (d) alert()
28. 28.⚡ Which word makes a new variable? (a) make (b) let (c) give (d) put
29. 29.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 3;
    console.log(x + y); (a) Error (b) 12 (c) 93
30. 30.⚡ 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
31. 31.⚡ What does this code show?
    let name = "Kabir";
    console.log("Well done, " + name + "!"); (a) Well done, Kabir! (b) name (c) Kabir (d) Well done, name!
32. 32.⚡ What number does this code print?
    let books = 8;
    books = books + 10;
    books = books - 10;
    console.log(books);
33. 33.⚡ Which JavaScript word makes a new variable? (a) alert() (b) for (c) let (d) if
34. 34.⚡ What number does this code print?
    let marks = 29;
    marks = marks + 11;
    marks = marks - 1;
    console.log(marks);
35. 35.⚡ What number does this code print?
    let a = 6;
    let b = 6;
    console.log(a * b);
36. 36.⚡ What does this code show?
    let name = "Zoya";
    console.log("Welcome, " + name + "!"); (a) Zoya (b) Welcome, Zoya! (c) name (d) Welcome, name!
37. 37.⚡ What number does this code print?
    let marks = 28;
    marks = marks + 11;
    marks = marks - 4;
    console.log(marks);
38. 38.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 6;
    console.log(x + y); (a) Error (b) 8 (c) 26
39. 39.⚡ What number does this code print?
    let a = 38;
    let b = 38;
    console.log(a + b);
40. 40.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) Kabir (c) Hello, Kabir! (d) name

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