JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 112 · 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 JavaScript add to a web page? (a) the domain name (b) actions and changes (c) only colours (d) the page title
2. 2.⚡ What does this code print? (Look at the quotes!)
   let x = "5";
   let y = 1;
   console.log(x + y); (a) 6 (b) 51 (c) Error
3. 3.⚡ What number does this code print?
   let runs = 29;
   runs = runs + 14;
   runs = runs - 1;
   console.log(runs);
4. 4.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <js> (c) <script> (d) <style>
5. 5.⚡ Which JavaScript word runs code when true? (a) alert() (b) if (c) for (d) console.log()
6. 6.⚡ What number does this code print?
   let coins = 12;
   coins = coins + 6;
   coins = coins - 17;
   console.log(coins);
7. 7.⚡ What does this code show?
   let name = "Riya";
   alert("Well done, " + name + "!"); (a) Well done, name! (b) Well done, Riya! (c) name (d) Riya
8. 8.⚡ What does this code show?
   let name = "Kabir";
   alert("Hi, " + name + "!"); (a) Kabir (b) Hi, name! (c) Hi, Kabir! (d) name
9. 9.⚡ What does this code show?
   let name = "Arjun";
   alert("Welcome, " + name + "!"); (a) name (b) Welcome, Arjun! (c) Welcome, name! (d) Arjun
10. 10.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 6;
    console.log(x + y); (a) 15 (b) Error (c) 96
11. 11.⚡ What number does this code print?
    let apples = 22;
    apples = apples + 2;
    apples = apples - 18;
    console.log(apples);
12. 12.⚡ Which JavaScript word makes a new variable? (a) alert() (b) let (c) for (d) console.log()
13. 13.⚡ What number does this code print?
    let books = 25;
    books = books + 7;
    books = books - 24;
    console.log(books);
14. 14.⚡ What does alert() show? (a) a new tab (b) a pop-up box (c) a table (d) a picture
15. 15.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 7;
    console.log(x + y); (a) Error (b) 17 (c) 8
16. 16.⚡ What number does this code print?
    let a = 50;
    let b = 25;
    console.log(a - b);
17. 17.⚡ What number does this code print?
    let marks = 30;
    marks = marks + 7;
    marks = marks - 37;
    console.log(marks);
18. 18.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 8;
    console.log(x + y); (a) 15 (b) Error (c) 78
19. 19.⚡ 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
20. 20.⚡ What number does this code print?
    let books = 28;
    books = books + 17;
    books = books - 8;
    console.log(books);
21. 21.⚡ Which JavaScript word shows a pop-up box? (a) for (b) let (c) console.log() (d) alert()
22. 22.⚡ What number does this code print?
    let a = 24;
    let b = 6;
    console.log(a - b);
23. 23.⚡ Which JavaScript word writes in the console? (a) for (b) let (c) console.log() (d) alert()
24. 24.⚡ What number does this code print?
    let apples = 17;
    apples = apples + 18;
    apples = apples - 21;
    console.log(apples);
25. 25.⚡ What number does this code print?
    let marks = 17;
    marks = marks + 5;
    marks = marks - 7;
    console.log(marks);
26. 26.⚡ Which word makes a new variable? (a) put (b) give (c) let (d) make
27. 27.⚡ What does this code show?
    let name = "Arjun";
    console.log("Hi, " + name + "!"); (a) Hi, name! (b) Arjun (c) Hi, Arjun! (d) name
28. 28.⚡ What does this code show?
    let name = "Zoya";
    alert("Welcome, " + name + "!"); (a) Welcome, name! (b) Zoya (c) Welcome, Zoya! (d) name
29. 29.⚡ What number does this code print?
    let a = 58;
    let b = 2;
    console.log(a + b);
30. 30.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 9;
    console.log(x + y); (a) Error (b) 29 (c) 11
31. 31.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 8;
    console.log(x + y); (a) 11 (b) 38 (c) Error
32. 32.⚡ Which JavaScript word repeats code? (a) alert() (b) for (c) console.log() (d) if
33. 33.⚡ What number does this code print?
    let marks = 19;
    marks = marks + 15;
    marks = marks - 16;
    console.log(marks);
34. 34.⚡ What does this code show?
    let name = "Aman";
    console.log("Hi, " + name + "!"); (a) Hi, Aman! (b) Aman (c) name (d) Hi, name!
35. 35.⚡ What number does this code print?
    let marks = 10;
    marks = marks + 16;
    marks = marks - 8;
    console.log(marks);
36. 36.⚡ What number does this code print?
    let a = 5;
    let b = 7;
    console.log(a * b);
37. 37.⚡ What number does this code print?
    let a = 13;
    let b = 9;
    console.log(a - b);
38. 38.⚡ What number does this code print?
    let coins = 28;
    coins = coins + 9;
    coins = coins - 32;
    console.log(coins);
39. 39.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .html (c) .css (d) .jpg
40. 40.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 8;
    console.log(x + y); (a) Error (b) 17 (c) 98

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