JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 23 · 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 number does this code print?
   let a = 41;
   let b = 2;
   console.log(a + b);
2. 2.⚡ Which JavaScript word repeats code? (a) let (b) alert() (c) if (d) for
3. 3.⚡ What does alert() show? (a) a pop-up box (b) a table (c) a picture (d) a new tab
4. 4.⚡ What does this code show?
   let name = "Meera";
   console.log("Well done, " + name + "!"); (a) name (b) Well done, name! (c) Well done, Meera! (d) Meera
5. 5.⚡ What does this code show?
   let name = "Kabir";
   alert("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Hello, Kabir! (d) Kabir
6. 6.⚡ What does this code print? (Look at the quotes!)
   let x = "6";
   let y = 3;
   console.log(x + y); (a) 9 (b) 63 (c) Error
7. 7.⚡ What does JavaScript add to a web page? (a) only colours (b) the page title (c) the domain name (d) actions and changes
8. 8.⚡ What number does this code print?
   let coins = 6;
   coins = coins + 15;
   coins = coins - 11;
   console.log(coins);
9. 9.⚡ What number does this code print?
   let a = 23;
   let b = 18;
   console.log(a - b);
10. 10.⚡ What number does this code print?
    let a = 19;
    let b = 34;
    console.log(a + b);
11. 11.⚡ What number does this code print?
    let a = 3;
    let b = 2;
    console.log(a * b);
12. 12.⚡ What does this code show?
    let name = "Zoya";
    alert("Welcome, " + name + "!"); (a) Zoya (b) Welcome, Zoya! (c) Welcome, name! (d) name
13. 13.⚡ Which JavaScript word shows a pop-up box? (a) let (b) for (c) console.log() (d) alert()
14. 14.⚡ What number does this code print?
    let books = 30;
    books = books + 7;
    books = books - 26;
    console.log(books);
15. 15.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .html (c) .jpg (d) .css
16. 16.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 3;
    console.log(x + y); (a) Error (b) 6 (c) 33
17. 17.⚡ What number does this code print?
    let a = 27;
    let b = 27;
    console.log(a + b);
18. 18.⚡ What number does this code print?
    let score = 29;
    score = score + 20;
    score = score - 49;
    console.log(score);
19. 19.⚡ What does this code show?
    let name = "Kabir";
    alert("Hi, " + name + "!"); (a) name (b) Kabir (c) Hi, Kabir! (d) Hi, name!
20. 20.⚡ Which tag holds JavaScript in a page? (a) <script> (b) <style> (c) <js> (d) <code>
21. 21.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 7;
    console.log(x + y); (a) 17 (b) Error (c) 8
22. 22.⚡ Which word makes a new variable? (a) put (b) give (c) let (d) make
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 runs = 21;
    runs = runs + 3;
    runs = runs - 5;
    console.log(runs);
25. 25.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 8;
    console.log(x + y); (a) Error (b) 9 (c) 18
26. 26.⚡ What number does this code print?
    let a = 7;
    let b = 2;
    console.log(a * b);
27. 27.⚡ What number does this code print?
    let a = 8;
    let b = 12;
    console.log(a * b);
28. 28.⚡ 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
29. 29.⚡ What number does this code print?
    let marks = 29;
    marks = marks + 2;
    marks = marks - 13;
    console.log(marks);
30. 30.⚡ What number does this code print?
    let runs = 22;
    runs = runs + 4;
    runs = runs - 14;
    console.log(runs);
31. 31.⚡ What number does this code print?
    let apples = 25;
    apples = apples + 17;
    apples = apples - 14;
    console.log(apples);
32. 32.⚡ Which JavaScript word makes a new variable? (a) if (b) alert() (c) console.log() (d) let
33. 33.⚡ Where does console.log() show its output? (a) in the console (b) in the address bar (c) on the title bar (d) on the printer
34. 34.⚡ What number does this code print?
    let score = 13;
    score = score + 15;
    score = score - 12;
    console.log(score);
35. 35.⚡ What does this code show?
    let name = "Arjun";
    alert("Welcome, " + name + "!"); (a) Arjun (b) Welcome, name! (c) name (d) Welcome, Arjun!
36. 36.⚡ What number does this code print?
    let a = 9;
    let b = 11;
    console.log(a + b);
37. 37.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 6;
    console.log(x + y); (a) 9 (b) 36 (c) Error
38. 38.⚡ What number does this code print?
    let apples = 9;
    apples = apples + 9;
    apples = apples - 3;
    console.log(apples);
39. 39.⚡ What number does this code print?
    let marks = 20;
    marks = marks + 3;
    marks = marks - 23;
    console.log(marks);
40. 40.⚡ What number does this code print?
    let marks = 16;
    marks = marks + 14;
    marks = marks - 14;
    console.log(marks);

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