JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 780 · 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 writes in the console? (a) if (b) console.log() (c) for (d) let
2. 2.⚡ Which JavaScript word makes a new variable? (a) let (b) alert() (c) if (d) console.log()
3. 3.⚡ Which JavaScript word shows a pop-up box? (a) if (b) console.log() (c) let (d) alert()
4. 4.⚡ What does this code print? (Look at the quotes!)
   let x = "4";
   let y = 2;
   console.log(x + y); (a) Error (b) 42 (c) 6
5. 5.⚡ What number does this code print?
   let runs = 27;
   runs = runs + 13;
   runs = runs - 22;
   console.log(runs);
6. 6.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .html (c) .js (d) .jpg
7. 7.⚡ What does this code print? (Look at the quotes!)
   let x = "7";
   let y = 9;
   console.log(x + y); (a) Error (b) 16 (c) 79
8. 8.⚡ What does this code print? (Look at the quotes!)
   let x = "2";
   let y = 8;
   console.log(x + y); (a) Error (b) 28 (c) 10
9. 9.⚡ What does this code print? (Look at the quotes!)
   let x = "5";
   let y = 8;
   console.log(x + y); (a) 13 (b) Error (c) 58
10. 10.⚡ What does this code show?
    let name = "Meera";
    alert("Hi, " + name + "!"); (a) name (b) Hi, name! (c) Hi, Meera! (d) Meera
11. 11.⚡ What does this code show?
    let name = "Kabir";
    alert("Welcome, " + name + "!"); (a) Kabir (b) name (c) Welcome, Kabir! (d) Welcome, name!
12. 12.⚡ What number does this code print?
    let score = 17;
    score = score + 14;
    score = score - 18;
    console.log(score);
13. 13.⚡ What number does this code print?
    let a = 9;
    let b = 33;
    console.log(a + b);
14. 14.⚡ Where does console.log() show its output? (a) on the printer (b) in the address bar (c) in the console (d) on the title bar
15. 15.⚡ Which JavaScript word runs code when true? (a) console.log() (b) for (c) if (d) alert()
16. 16.⚡ What does this code show?
    let name = "Aman";
    alert("Welcome, " + name + "!"); (a) name (b) Aman (c) Welcome, Aman! (d) Welcome, name!
17. 17.⚡ What number does this code print?
    let apples = 16;
    apples = apples + 8;
    apples = apples - 14;
    console.log(apples);
18. 18.⚡ What does alert() show? (a) a picture (b) a new tab (c) a pop-up box (d) a table
19. 19.⚡ What number does this code print?
    let score = 17;
    score = score + 15;
    score = score - 25;
    console.log(score);
20. 20.⚡ What number does this code print?
    let books = 7;
    books = books + 20;
    books = books - 19;
    console.log(books);
21. 21.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 2;
    console.log(x + y); (a) 10 (b) Error (c) 82
22. 22.⚡ What number does this code print?
    let score = 28;
    score = score + 17;
    score = score - 41;
    console.log(score);
23. 23.⚡ What number does this code print?
    let a = 54;
    let b = 28;
    console.log(a + b);
24. 24.⚡ What number does this code print?
    let marks = 14;
    marks = marks + 5;
    marks = marks - 15;
    console.log(marks);
25. 25.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <code> (c) <js> (d) <script>
26. 26.⚡ Which JavaScript word repeats code? (a) alert() (b) let (c) if (d) for
27. 27.⚡ What number does this code print?
    let a = 37;
    let b = 29;
    console.log(a - b);
28. 28.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 6;
    console.log(x + y); (a) 46 (b) Error (c) 10
29. 29.⚡ What does JavaScript add to a web page? (a) actions and changes (b) the page title (c) only colours (d) the domain name
30. 30.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 6;
    console.log(x + y); (a) Error (b) 26 (c) 8
31. 31.⚡ What does this code show?
    let name = "Arjun";
    alert("Welcome, " + name + "!"); (a) Welcome, name! (b) Arjun (c) Welcome, Arjun! (d) name
32. 32.⚡ What does this code show?
    let name = "Meera";
    alert("Welcome, " + name + "!"); (a) Welcome, name! (b) Meera (c) name (d) Welcome, Meera!
33. 33.⚡ What number does this code print?
    let score = 26;
    score = score + 5;
    score = score - 17;
    console.log(score);
34. 34.⚡ What number does this code print?
    let books = 9;
    books = books + 11;
    books = books - 12;
    console.log(books);
35. 35.⚡ What number does this code print?
    let marks = 20;
    marks = marks + 16;
    marks = marks - 20;
    console.log(marks);
36. 36.⚡ What number does this code print?
    let books = 7;
    books = books + 13;
    books = books - 16;
    console.log(books);
37. 37.⚡ What number does this code print?
    let books = 17;
    books = books + 6;
    books = books - 14;
    console.log(books);
38. 38.⚡ What does this code show?
    let name = "Riya";
    console.log("Well done, " + name + "!"); (a) Riya (b) Well done, Riya! (c) name (d) Well done, name!
39. 39.⚡ What number does this code print?
    let marks = 24;
    marks = marks + 16;
    marks = marks - 18;
    console.log(marks);
40. 40.⚡ What does this code show?
    let name = "Kabir";
    alert("Hi, " + name + "!"); (a) Hi, Kabir! (b) Kabir (c) Hi, name! (d) name

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