JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 141 · 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 = 35;
   let b = 30;
   console.log(a + b);
2. 2.⚡ Which JavaScript word writes in the console? (a) alert() (b) if (c) for (d) console.log()
3. 3.⚡ What number does this code print?
   let runs = 18;
   runs = runs + 20;
   runs = runs - 1;
   console.log(runs);
4. 4.⚡ Which word makes a new variable? (a) make (b) give (c) put (d) let
5. 5.⚡ Which JavaScript word makes a new variable? (a) alert() (b) if (c) for (d) let
6. 6.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .css (c) .jpg (d) .html
7. 7.⚡ What number does this code print?
   let a = 24;
   let b = 7;
   console.log(a - b);
8. 8.⚡ What does JavaScript add to a web page? (a) the page title (b) the domain name (c) actions and changes (d) only colours
9. 9.⚡ What number does this code print?
   let a = 4;
   let b = 2;
   console.log(a * b);
10. 10.⚡ 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
11. 11.⚡ What does this code show?
    let name = "Zoya";
    console.log("Welcome, " + name + "!"); (a) Zoya (b) Welcome, name! (c) Welcome, Zoya! (d) name
12. 12.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 2;
    console.log(x + y); (a) 3 (b) 12 (c) Error
13. 13.⚡ What does this code show?
    let name = "Kabir";
    alert("Well done, " + name + "!"); (a) Kabir (b) name (c) Well done, name! (d) Well done, Kabir!
14. 14.⚡ What number does this code print?
    let apples = 5;
    apples = apples + 10;
    apples = apples - 5;
    console.log(apples);
15. 15.⚡ What number does this code print?
    let score = 28;
    score = score + 2;
    score = score - 11;
    console.log(score);
16. 16.⚡ What number does this code print?
    let a = 6;
    let b = 10;
    console.log(a * b);
17. 17.⚡ What does this code show?
    let name = "Kabir";
    console.log("Welcome, " + name + "!"); (a) Kabir (b) name (c) Welcome, name! (d) Welcome, Kabir!
18. 18.⚡ Which JavaScript word runs code when true? (a) alert() (b) if (c) for (d) let
19. 19.⚡ 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
20. 20.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 4;
    console.log(x + y); (a) 14 (b) Error (c) 5
21. 21.⚡ What does this code show?
    let name = "Arjun";
    alert("Hi, " + name + "!"); (a) Arjun (b) Hi, Arjun! (c) Hi, name! (d) name
22. 22.⚡ What number does this code print?
    let apples = 13;
    apples = apples + 5;
    apples = apples - 5;
    console.log(apples);
23. 23.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <code> (c) <script> (d) <js>
24. 24.⚡ Which JavaScript word repeats code? (a) for (b) console.log() (c) if (d) let
25. 25.⚡ What number does this code print?
    let runs = 20;
    runs = runs + 4;
    runs = runs - 24;
    console.log(runs);
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 5;
    console.log(x + y); (a) 7 (b) 25 (c) Error
27. 27.⚡ What number does this code print?
    let a = 7;
    let b = 5;
    console.log(a * b);
28. 28.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 5;
    console.log(x + y); (a) Error (b) 9 (c) 45
29. 29.⚡ What number does this code print?
    let a = 7;
    let b = 11;
    console.log(a * b);
30. 30.⚡ What number does this code print?
    let marks = 15;
    marks = marks + 3;
    marks = marks - 7;
    console.log(marks);
31. 31.⚡ What number does this code print?
    let runs = 8;
    runs = runs + 5;
    runs = runs - 3;
    console.log(runs);
32. 32.⚡ What number does this code print?
    let books = 25;
    books = books + 16;
    books = books - 41;
    console.log(books);
33. 33.⚡ What number does this code print?
    let runs = 26;
    runs = runs + 10;
    runs = runs - 1;
    console.log(runs);
34. 34.⚡ What number does this code print?
    let a = 47;
    let b = 28;
    console.log(a - b);
35. 35.⚡ What number does this code print?
    let a = 7;
    let b = 12;
    console.log(a * b);
36. 36.⚡ What does this code show?
    let name = "Aman";
    console.log("Well done, " + name + "!"); (a) name (b) Well done, Aman! (c) Well done, name! (d) Aman
37. 37.⚡ What does this code show?
    let name = "Meera";
    console.log("Hi, " + name + "!"); (a) Meera (b) Hi, name! (c) name (d) Hi, Meera!
38. 38.⚡ What does alert() show? (a) a new tab (b) a picture (c) a table (d) a pop-up box
39. 39.⚡ What does this code show?
    let name = "Zoya";
    console.log("Well done, " + name + "!"); (a) name (b) Well done, Zoya! (c) Well done, name! (d) Zoya
40. 40.⚡ What does this code show?
    let name = "Aman";
    console.log("Hello, " + name + "!"); (a) Hello, Aman! (b) name (c) Aman (d) Hello, name!

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