JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 556 · 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 = "1";
   let y = 8;
   console.log(x + y); (a) 18 (b) 9 (c) Error
2. 2.⚡ What number does this code print?
   let a = 47;
   let b = 3;
   console.log(a + b);
3. 3.⚡ Which JavaScript word runs code when true? (a) if (b) let (c) console.log() (d) alert()
4. 4.⚡ Which JavaScript word makes a new variable? (a) alert() (b) if (c) console.log() (d) let
5. 5.⚡ What does this code print? (Look at the quotes!)
   let x = "4";
   let y = 7;
   console.log(x + y); (a) 11 (b) 47 (c) Error
6. 6.⚡ What does this code show?
   let name = "Riya";
   alert("Well done, " + name + "!"); (a) Well done, Riya! (b) Well done, name! (c) Riya (d) name
7. 7.⚡ What does alert() show? (a) a table (b) a new tab (c) a pop-up box (d) a picture
8. 8.⚡ What does this code print? (Look at the quotes!)
   let x = "1";
   let y = 4;
   console.log(x + y); (a) 5 (b) Error (c) 14
9. 9.⚡ Which word makes a new variable? (a) give (b) make (c) let (d) put
10. 10.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <code> (c) <script> (d) <js>
11. 11.⚡ What does this code show?
    let name = "Arjun";
    console.log("Hi, " + name + "!"); (a) Hi, name! (b) name (c) Hi, Arjun! (d) Arjun
12. 12.⚡ Which JavaScript word writes in the console? (a) console.log() (b) for (c) let (d) if
13. 13.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 2;
    console.log(x + y); (a) Error (b) 72 (c) 9
14. 14.⚡ What number does this code print?
    let a = 15;
    let b = 10;
    console.log(a + b);
15. 15.⚡ What does JavaScript add to a web page? (a) the page title (b) only colours (c) actions and changes (d) the domain name
16. 16.⚡ Which JavaScript word shows a pop-up box? (a) for (b) alert() (c) let (d) console.log()
17. 17.⚡ What number does this code print?
    let score = 13;
    score = score + 12;
    score = score - 19;
    console.log(score);
18. 18.⚡ What number does this code print?
    let a = 38;
    let b = 5;
    console.log(a + b);
19. 19.⚡ What number does this code print?
    let books = 17;
    books = books + 9;
    books = books - 3;
    console.log(books);
20. 20.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 8;
    console.log(x + y); (a) 13 (b) 58 (c) Error
21. 21.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 7;
    console.log(x + y); (a) 16 (b) 97 (c) Error
22. 22.⚡ What number does this code print?
    let apples = 26;
    apples = apples + 6;
    apples = apples - 26;
    console.log(apples);
23. 23.⚡ Which JavaScript word repeats code? (a) console.log() (b) for (c) let (d) alert()
24. 24.⚡ What number does this code print?
    let runs = 16;
    runs = runs + 3;
    runs = runs - 4;
    console.log(runs);
25. 25.⚡ Where does console.log() show its output? (a) on the printer (b) on the title bar (c) in the address bar (d) in the console
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 4;
    console.log(x + y); (a) Error (b) 94 (c) 13
27. 27.⚡ What number does this code print?
    let a = 2;
    let b = 9;
    console.log(a * b);
28. 28.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 1;
    console.log(x + y); (a) Error (b) 4 (c) 31
29. 29.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 9;
    console.log(x + y); (a) 11 (b) 29 (c) Error
30. 30.⚡ What does this code show?
    let name = "Kabir";
    alert("Well done, " + name + "!"); (a) name (b) Well done, Kabir! (c) Well done, name! (d) Kabir
31. 31.⚡ What does this code show?
    let name = "Aman";
    console.log("Hi, " + name + "!"); (a) name (b) Hi, name! (c) Hi, Aman! (d) Aman
32. 32.⚡ What does this code show?
    let name = "Aman";
    alert("Welcome, " + name + "!"); (a) name (b) Welcome, name! (c) Welcome, Aman! (d) Aman
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 6;
    console.log(x + y); (a) 9 (b) Error (c) 36
34. 34.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 1;
    console.log(x + y); (a) 9 (b) Error (c) 81
35. 35.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 3;
    console.log(x + y); (a) Error (b) 23 (c) 5
36. 36.⚡ What number does this code print?
    let a = 16;
    let b = 12;
    console.log(a - b);
37. 37.⚡ A JavaScript file usually ends with which extension? (a) .jpg (b) .html (c) .js (d) .css
38. 38.⚡ What number does this code print?
    let books = 23;
    books = books + 7;
    books = books - 2;
    console.log(books);
39. 39.⚡ What does this code show?
    let name = "Zoya";
    console.log("Welcome, " + name + "!"); (a) Zoya (b) name (c) Welcome, name! (d) Welcome, Zoya!
40. 40.⚡ What number does this code print?
    let a = 9;
    let b = 30;
    console.log(a + b);

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