JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 831 · 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 = 7;
   console.log(x + y); (a) 37 (b) 10 (c) Error
2. 2.⚡ Which JavaScript word writes in the console? (a) alert() (b) console.log() (c) if (d) for
3. 3.⚡ What does this code print? (Look at the quotes!)
   let x = "5";
   let y = 7;
   console.log(x + y); (a) 12 (b) Error (c) 57
4. 4.⚡ What number does this code print?
   let a = 48;
   let b = 7;
   console.log(a + b);
5. 5.⚡ What number does this code print?
   let apples = 20;
   apples = apples + 10;
   apples = apples - 13;
   console.log(apples);
6. 6.⚡ What number does this code print?
   let books = 15;
   books = books + 6;
   books = books - 16;
   console.log(books);
7. 7.⚡ What number does this code print?
   let runs = 22;
   runs = runs + 6;
   runs = runs - 13;
   console.log(runs);
8. 8.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <script> (c) <js> (d) <code>
9. 9.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .html (c) .jpg (d) .css
10. 10.⚡ What number does this code print?
    let score = 7;
    score = score + 11;
    score = score - 8;
    console.log(score);
11. 11.⚡ What number does this code print?
    let score = 17;
    score = score + 6;
    score = score - 15;
    console.log(score);
12. 12.⚡ What does this code show?
    let name = "Meera";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) Meera (c) Hello, Meera! (d) name
13. 13.⚡ What number does this code print?
    let a = 46;
    let b = 14;
    console.log(a + b);
14. 14.⚡ What number does this code print?
    let apples = 15;
    apples = apples + 5;
    apples = apples - 12;
    console.log(apples);
15. 15.⚡ What does this code show?
    let name = "Riya";
    console.log("Hello, " + name + "!"); (a) name (b) Hello, name! (c) Hello, Riya! (d) Riya
16. 16.⚡ What does this code show?
    let name = "Riya";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) Riya (c) Hello, Riya! (d) name
17. 17.⚡ Which JavaScript word shows a pop-up box? (a) console.log() (b) if (c) for (d) alert()
18. 18.⚡ What number does this code print?
    let a = 12;
    let b = 5;
    console.log(a * b);
19. 19.⚡ What does this code show?
    let name = "Riya";
    alert("Well done, " + name + "!"); (a) Well done, Riya! (b) name (c) Well done, name! (d) Riya
20. 20.⚡ What does this code show?
    let name = "Arjun";
    alert("Well done, " + name + "!"); (a) Well done, Arjun! (b) Arjun (c) Well done, name! (d) name
21. 21.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hello, " + name + "!"); (a) Hello, Kabir! (b) Kabir (c) Hello, name! (d) name
22. 22.⚡ What number does this code print?
    let books = 26;
    books = books + 14;
    books = books - 10;
    console.log(books);
23. 23.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 6;
    console.log(x + y); (a) 26 (b) 8 (c) Error
24. 24.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 3;
    console.log(x + y); (a) 8 (b) Error (c) 53
25. 25.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 3;
    console.log(x + y); (a) 33 (b) 6 (c) Error
26. 26.⚡ What number does this code print?
    let a = 16;
    let b = 4;
    console.log(a + b);
27. 27.⚡ What number does this code print?
    let a = 5;
    let b = 6;
    console.log(a * b);
28. 28.⚡ Which JavaScript word runs code when true? (a) for (b) if (c) console.log() (d) let
29. 29.⚡ What does JavaScript add to a web page? (a) actions and changes (b) only colours (c) the page title (d) the domain name
30. 30.⚡ Where does console.log() show its output? (a) in the address bar (b) on the title bar (c) in the console (d) on the printer
31. 31.⚡ What number does this code print?
    let a = 47;
    let b = 23;
    console.log(a + b);
32. 32.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 1;
    console.log(x + y); (a) Error (b) 6 (c) 51
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 8;
    console.log(x + y); (a) Error (b) 15 (c) 78
34. 34.⚡ What does alert() show? (a) a pop-up box (b) a picture (c) a new tab (d) a table
35. 35.⚡ What number does this code print?
    let a = 8;
    let b = 6;
    console.log(a * b);
36. 36.⚡ What does this code show?
    let name = "Zoya";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Zoya (d) Hello, Zoya!
37. 37.⚡ What does this code show?
    let name = "Arjun";
    alert("Hello, " + name + "!"); (a) name (b) Hello, Arjun! (c) Hello, name! (d) Arjun
38. 38.⚡ Which JavaScript word repeats code? (a) alert() (b) console.log() (c) for (d) let
39. 39.⚡ What number does this code print?
    let score = 27;
    score = score + 2;
    score = score - 24;
    console.log(score);
40. 40.⚡ What does this code show?
    let name = "Riya";
    alert("Welcome, " + name + "!"); (a) Welcome, Riya! (b) name (c) Welcome, name! (d) Riya

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