JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 414 · 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 = 3;
   let b = 2;
   console.log(a * b);
2. 2.⚡ What number does this code print?
   let a = 48;
   let b = 9;
   console.log(a - b);
3. 3.⚡ Where does console.log() show its output? (a) on the title bar (b) in the address bar (c) on the printer (d) in the console
4. 4.⚡ Which JavaScript word makes a new variable? (a) if (b) console.log() (c) for (d) let
5. 5.⚡ What number does this code print?
   let a = 36;
   let b = 32;
   console.log(a - b);
6. 6.⚡ What number does this code print?
   let a = 50;
   let b = 20;
   console.log(a + b);
7. 7.⚡ What does JavaScript add to a web page? (a) only colours (b) the page title (c) the domain name (d) actions and changes
8. 8.⚡ Which JavaScript word writes in the console? (a) if (b) console.log() (c) for (d) alert()
9. 9.⚡ Which JavaScript word shows a pop-up box? (a) let (b) if (c) console.log() (d) alert()
10. 10.⚡ What number does this code print?
    let score = 30;
    score = score + 13;
    score = score - 8;
    console.log(score);
11. 11.⚡ What number does this code print?
    let a = 24;
    let b = 30;
    console.log(a + b);
12. 12.⚡ What number does this code print?
    let a = 11;
    let b = 35;
    console.log(a + b);
13. 13.⚡ Which JavaScript word runs code when true? (a) if (b) let (c) for (d) console.log()
14. 14.⚡ Which word makes a new variable? (a) put (b) give (c) let (d) make
15. 15.⚡ What does this code show?
    let name = "Riya";
    alert("Hello, " + name + "!"); (a) name (b) Riya (c) Hello, Riya! (d) Hello, name!
16. 16.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 7;
    console.log(x + y); (a) 97 (b) Error (c) 16
17. 17.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 1;
    console.log(x + y); (a) Error (b) 41 (c) 5
18. 18.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 1;
    console.log(x + y); (a) 81 (b) 9 (c) Error
19. 19.⚡ What number does this code print?
    let a = 34;
    let b = 6;
    console.log(a + b);
20. 20.⚡ What number does this code print?
    let a = 26;
    let b = 1;
    console.log(a - b);
21. 21.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 4;
    console.log(x + y); (a) 10 (b) Error (c) 64
22. 22.⚡ What number does this code print?
    let a = 16;
    let b = 39;
    console.log(a + b);
23. 23.⚡ What number does this code print?
    let marks = 17;
    marks = marks + 5;
    marks = marks - 7;
    console.log(marks);
24. 24.⚡ What does this code show?
    let name = "Riya";
    alert("Welcome, " + name + "!"); (a) name (b) Riya (c) Welcome, name! (d) Welcome, Riya!
25. 25.⚡ What does alert() show? (a) a picture (b) a new tab (c) a table (d) a pop-up box
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 7;
    console.log(x + y); (a) Error (b) 57 (c) 12
27. 27.⚡ What number does this code print?
    let a = 10;
    let b = 11;
    console.log(a * b);
28. 28.⚡ What does this code show?
    let name = "Meera";
    alert("Hi, " + name + "!"); (a) Hi, name! (b) Meera (c) Hi, Meera! (d) name
29. 29.⚡ What number does this code print?
    let a = 10;
    let b = 14;
    console.log(a + b);
30. 30.⚡ What number does this code print?
    let score = 21;
    score = score + 17;
    score = score - 2;
    console.log(score);
31. 31.⚡ What number does this code print?
    let runs = 19;
    runs = runs + 11;
    runs = runs - 1;
    console.log(runs);
32. 32.⚡ What number does this code print?
    let a = 41;
    let b = 20;
    console.log(a - b);
33. 33.⚡ Which JavaScript word repeats code? (a) let (b) if (c) for (d) console.log()
34. 34.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hi, " + name + "!"); (a) Hi, name! (b) Kabir (c) name (d) Hi, Kabir!
35. 35.⚡ What does this code show?
    let name = "Aman";
    alert("Well done, " + name + "!"); (a) Well done, Aman! (b) Aman (c) name (d) Well done, name!
36. 36.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 2;
    console.log(x + y); (a) Error (b) 22 (c) 4
37. 37.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 3;
    console.log(x + y); (a) 53 (b) Error (c) 8
38. 38.⚡ What number does this code print?
    let books = 24;
    books = books + 12;
    books = books - 9;
    console.log(books);
39. 39.⚡ What number does this code print?
    let a = 26;
    let b = 32;
    console.log(a + b);
40. 40.⚡ What number does this code print?
    let a = 13;
    let b = 4;
    console.log(a - b);

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