JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 360 · 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 = "3";
   let y = 1;
   console.log(x + y); (a) 31 (b) 4 (c) Error
2. 2.⚡ What number does this code print?
   let a = 41;
   let b = 16;
   console.log(a - b);
3. 3.⚡ What number does this code print?
   let coins = 12;
   coins = coins + 3;
   coins = coins - 15;
   console.log(coins);
4. 4.⚡ 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
5. 5.⚡ What does this code show?
   let name = "Arjun";
   console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) name (c) Welcome, Arjun! (d) Arjun
6. 6.⚡ What number does this code print?
   let runs = 13;
   runs = runs + 18;
   runs = runs - 8;
   console.log(runs);
7. 7.⚡ Which word makes a new variable? (a) make (b) put (c) give (d) let
8. 8.⚡ What does this code show?
   let name = "Arjun";
   console.log("Hello, " + name + "!"); (a) Hello, name! (b) Hello, Arjun! (c) name (d) Arjun
9. 9.⚡ Which JavaScript word makes a new variable? (a) console.log() (b) let (c) for (d) alert()
10. 10.⚡ Which JavaScript word repeats code? (a) let (b) if (c) console.log() (d) for
11. 11.⚡ What number does this code print?
    let apples = 9;
    apples = apples + 9;
    apples = apples - 6;
    console.log(apples);
12. 12.⚡ What number does this code print?
    let marks = 29;
    marks = marks + 6;
    marks = marks - 16;
    console.log(marks);
13. 13.⚡ Which JavaScript word writes in the console? (a) alert() (b) let (c) if (d) console.log()
14. 14.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) let (c) if (d) for
15. 15.⚡ What number does this code print?
    let a = 18;
    let b = 40;
    console.log(a + b);
16. 16.⚡ What number does this code print?
    let a = 53;
    let b = 37;
    console.log(a - b);
17. 17.⚡ What number does this code print?
    let a = 34;
    let b = 12;
    console.log(a + b);
18. 18.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 9;
    console.log(x + y); (a) 12 (b) Error (c) 39
19. 19.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 6;
    console.log(x + y); (a) Error (b) 76 (c) 13
20. 20.⚡ What number does this code print?
    let books = 30;
    books = books + 19;
    books = books - 1;
    console.log(books);
21. 21.⚡ What number does this code print?
    let a = 35;
    let b = 19;
    console.log(a - b);
22. 22.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 5;
    console.log(x + y); (a) 85 (b) Error (c) 13
23. 23.⚡ Which JavaScript word runs code when true? (a) alert() (b) if (c) for (d) console.log()
24. 24.⚡ What number does this code print?
    let a = 2;
    let b = 3;
    console.log(a * b);
25. 25.⚡ What number does this code print?
    let apples = 22;
    apples = apples + 20;
    apples = apples - 20;
    console.log(apples);
26. 26.⚡ What does this code show?
    let name = "Meera";
    alert("Well done, " + name + "!"); (a) name (b) Well done, Meera! (c) Meera (d) Well done, name!
27. 27.⚡ What number does this code print?
    let marks = 19;
    marks = marks + 20;
    marks = marks - 1;
    console.log(marks);
28. 28.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .html (c) .jpg (d) .js
29. 29.⚡ What does this code show?
    let name = "Aman";
    alert("Hi, " + name + "!"); (a) name (b) Hi, Aman! (c) Aman (d) Hi, name!
30. 30.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 6;
    console.log(x + y); (a) 96 (b) Error (c) 15
31. 31.⚡ What number does this code print?
    let a = 57;
    let b = 23;
    console.log(a + b);
32. 32.⚡ What number does this code print?
    let runs = 17;
    runs = runs + 13;
    runs = runs - 7;
    console.log(runs);
33. 33.⚡ What number does this code print?
    let apples = 9;
    apples = apples + 19;
    apples = apples - 16;
    console.log(apples);
34. 34.⚡ What does this code show?
    let name = "Zoya";
    console.log("Welcome, " + name + "!"); (a) Zoya (b) Welcome, Zoya! (c) Welcome, name! (d) name
35. 35.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <script> (c) <js> (d) <style>
36. 36.⚡ What does this code show?
    let name = "Aman";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Aman (d) Hello, Aman!
37. 37.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hello, " + name + "!"); (a) Hello, Kabir! (b) name (c) Kabir (d) Hello, name!
38. 38.⚡ What does alert() show? (a) a picture (b) a new tab (c) a pop-up box (d) a table
39. 39.⚡ What does this code show?
    let name = "Arjun";
    alert("Well done, " + name + "!"); (a) Arjun (b) Well done, name! (c) Well done, Arjun! (d) name
40. 40.⚡ 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

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