JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 854 · 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 = 11;
   let b = 17;
   console.log(a + b);
2. 2.⚡ What number does this code print?
   let a = 11;
   let b = 7;
   console.log(a * b);
3. 3.⚡ What does alert() show? (a) a pop-up box (b) a picture (c) a table (d) a new tab
4. 4.⚡ What does JavaScript add to a web page? (a) the domain name (b) actions and changes (c) the page title (d) only colours
5. 5.⚡ What does this code print? (Look at the quotes!)
   let x = "1";
   let y = 3;
   console.log(x + y); (a) Error (b) 4 (c) 13
6. 6.⚡ What does this code show?
   let name = "Kabir";
   alert("Hi, " + name + "!"); (a) name (b) Hi, name! (c) Hi, Kabir! (d) Kabir
7. 7.⚡ What number does this code print?
   let a = 10;
   let b = 4;
   console.log(a * b);
8. 8.⚡ Which JavaScript word shows a pop-up box? (a) let (b) console.log() (c) alert() (d) for
9. 9.⚡ What number does this code print?
   let a = 12;
   let b = 3;
   console.log(a * b);
10. 10.⚡ What number does this code print?
    let books = 11;
    books = books + 15;
    books = books - 9;
    console.log(books);
11. 11.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .jpg (c) .html (d) .css
12. 12.⚡ What does this code show?
    let name = "Meera";
    alert("Hello, " + name + "!"); (a) name (b) Meera (c) Hello, name! (d) Hello, Meera!
13. 13.⚡ What number does this code print?
    let a = 37;
    let b = 39;
    console.log(a + b);
14. 14.⚡ What number does this code print?
    let score = 17;
    score = score + 17;
    score = score - 15;
    console.log(score);
15. 15.⚡ What number does this code print?
    let a = 37;
    let b = 10;
    console.log(a - b);
16. 16.⚡ What does this code show?
    let name = "Arjun";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) name (c) Welcome, Arjun! (d) Arjun
17. 17.⚡ What number does this code print?
    let a = 8;
    let b = 2;
    console.log(a * b);
18. 18.⚡ What number does this code print?
    let a = 14;
    let b = 30;
    console.log(a + b);
19. 19.⚡ What does this code show?
    let name = "Aman";
    console.log("Hello, " + name + "!"); (a) Aman (b) Hello, name! (c) Hello, Aman! (d) name
20. 20.⚡ What does this code show?
    let name = "Riya";
    alert("Hi, " + name + "!"); (a) Hi, Riya! (b) name (c) Hi, name! (d) Riya
21. 21.⚡ Which JavaScript word writes in the console? (a) alert() (b) for (c) console.log() (d) let
22. 22.⚡ What does this code show?
    let name = "Meera";
    console.log("Welcome, " + name + "!"); (a) Meera (b) name (c) Welcome, Meera! (d) Welcome, name!
23. 23.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 2;
    console.log(x + y); (a) 9 (b) 72 (c) Error
24. 24.⚡ What number does this code print?
    let a = 11;
    let b = 4;
    console.log(a + b);
25. 25.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 2;
    console.log(x + y); (a) Error (b) 6 (c) 42
26. 26.⚡ What does this code show?
    let name = "Aman";
    alert("Well done, " + name + "!"); (a) Well done, Aman! (b) Aman (c) name (d) Well done, name!
27. 27.⚡ What number does this code print?
    let a = 33;
    let b = 16;
    console.log(a - b);
28. 28.⚡ Where does console.log() show its output? (a) in the address bar (b) on the printer (c) in the console (d) on the title bar
29. 29.⚡ Which JavaScript word repeats code? (a) let (b) alert() (c) console.log() (d) for
30. 30.⚡ Which tag holds JavaScript in a page? (a) <js> (b) <style> (c) <script> (d) <code>
31. 31.⚡ What number does this code print?
    let marks = 11;
    marks = marks + 7;
    marks = marks - 18;
    console.log(marks);
32. 32.⚡ What number does this code print?
    let apples = 7;
    apples = apples + 6;
    apples = apples - 4;
    console.log(apples);
33. 33.⚡ What number does this code print?
    let score = 8;
    score = score + 5;
    score = score - 12;
    console.log(score);
34. 34.⚡ What does this code show?
    let name = "Meera";
    console.log("Hi, " + name + "!"); (a) name (b) Hi, Meera! (c) Hi, name! (d) Meera
35. 35.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 3;
    console.log(x + y); (a) 5 (b) 23 (c) Error
36. 36.⚡ What number does this code print?
    let a = 8;
    let b = 21;
    console.log(a + b);
37. 37.⚡ Which word makes a new variable? (a) let (b) put (c) give (d) make
38. 38.⚡ What number does this code print?
    let coins = 30;
    coins = coins + 16;
    coins = coins - 20;
    console.log(coins);
39. 39.⚡ What number does this code print?
    let a = 19;
    let b = 4;
    console.log(a + b);
40. 40.⚡ What number does this code print?
    let a = 33;
    let b = 5;
    console.log(a - b);

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