JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 652 · 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 = 9;
   console.log(x + y); (a) 10 (b) Error (c) 19
2. 2.⚡ Which JavaScript word writes in the console? (a) alert() (b) console.log() (c) for (d) let
3. 3.⚡ What number does this code print?
   let books = 27;
   books = books + 9;
   books = books - 3;
   console.log(books);
4. 4.⚡ What number does this code print?
   let marks = 21;
   marks = marks + 8;
   marks = marks - 27;
   console.log(marks);
5. 5.⚡ What does this code print? (Look at the quotes!)
   let x = "5";
   let y = 9;
   console.log(x + y); (a) Error (b) 59 (c) 14
6. 6.⚡ Which JavaScript word shows a pop-up box? (a) let (b) alert() (c) for (d) if
7. 7.⚡ 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
8. 8.⚡ Which JavaScript word runs code when true? (a) console.log() (b) alert() (c) let (d) if
9. 9.⚡ What number does this code print?
   let a = 43;
   let b = 15;
   console.log(a + b);
10. 10.⚡ What number does this code print?
    let a = 48;
    let b = 22;
    console.log(a - b);
11. 11.⚡ What does this code show?
    let name = "Aman";
    console.log("Hello, " + name + "!"); (a) Aman (b) name (c) Hello, name! (d) Hello, Aman!
12. 12.⚡ What does this code show?
    let name = "Arjun";
    alert("Welcome, " + name + "!"); (a) name (b) Arjun (c) Welcome, Arjun! (d) Welcome, name!
13. 13.⚡ Which word makes a new variable? (a) give (b) make (c) let (d) put
14. 14.⚡ What does alert() show? (a) a pop-up box (b) a new tab (c) a picture (d) a table
15. 15.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .js (c) .jpg (d) .css
16. 16.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 6;
    console.log(x + y); (a) 14 (b) Error (c) 86
17. 17.⚡ What number does this code print?
    let apples = 23;
    apples = apples + 6;
    apples = apples - 26;
    console.log(apples);
18. 18.⚡ What number does this code print?
    let a = 18;
    let b = 14;
    console.log(a - b);
19. 19.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 3;
    console.log(x + y); (a) 6 (b) 33 (c) Error
20. 20.⚡ 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
21. 21.⚡ What number does this code print?
    let a = 26;
    let b = 20;
    console.log(a - b);
22. 22.⚡ What does JavaScript add to a web page? (a) the domain name (b) only colours (c) actions and changes (d) the page title
23. 23.⚡ What number does this code print?
    let score = 9;
    score = score + 20;
    score = score - 5;
    console.log(score);
24. 24.⚡ What number does this code print?
    let books = 11;
    books = books + 3;
    books = books - 13;
    console.log(books);
25. 25.⚡ What does this code show?
    let name = "Riya";
    alert("Welcome, " + name + "!"); (a) Riya (b) name (c) Welcome, name! (d) Welcome, Riya!
26. 26.⚡ What does this code show?
    let name = "Aman";
    console.log("Welcome, " + name + "!"); (a) Welcome, Aman! (b) Aman (c) Welcome, name! (d) name
27. 27.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 3;
    console.log(x + y); (a) 53 (b) 8 (c) Error
28. 28.⚡ What does this code show?
    let name = "Arjun";
    alert("Hi, " + name + "!"); (a) Hi, Arjun! (b) Arjun (c) name (d) Hi, name!
29. 29.⚡ What does this code show?
    let name = "Riya";
    console.log("Well done, " + name + "!"); (a) Riya (b) Well done, name! (c) Well done, Riya! (d) name
30. 30.⚡ Which JavaScript word repeats code? (a) console.log() (b) let (c) for (d) if
31. 31.⚡ What number does this code print?
    let score = 8;
    score = score + 14;
    score = score - 22;
    console.log(score);
32. 32.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 7;
    console.log(x + y); (a) Error (b) 47 (c) 11
33. 33.⚡ What does this code show?
    let name = "Zoya";
    console.log("Hi, " + name + "!"); (a) Hi, Zoya! (b) Zoya (c) name (d) Hi, name!
34. 34.⚡ What number does this code print?
    let a = 6;
    let b = 8;
    console.log(a * b);
35. 35.⚡ What number does this code print?
    let a = 14;
    let b = 15;
    console.log(a + b);
36. 36.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 1;
    console.log(x + y); (a) Error (b) 7 (c) 61
37. 37.⚡ What number does this code print?
    let score = 22;
    score = score + 7;
    score = score - 22;
    console.log(score);
38. 38.⚡ What does this code show?
    let name = "Zoya";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) Zoya (c) Welcome, Zoya! (d) name
39. 39.⚡ What number does this code print?
    let apples = 11;
    apples = apples + 19;
    apples = apples - 27;
    console.log(apples);
40. 40.⚡ What number does this code print?
    let runs = 7;
    runs = runs + 6;
    runs = runs - 2;
    console.log(runs);

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