JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 990 · 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 = 8;
   let b = 9;
   console.log(a * b);
2. 2.⚡ Which JavaScript word writes in the console? (a) let (b) console.log() (c) for (d) alert()
3. 3.⚡ What number does this code print?
   let a = 5;
   let b = 5;
   console.log(a * b);
4. 4.⚡ What does this code print? (Look at the quotes!)
   let x = "3";
   let y = 9;
   console.log(x + y); (a) Error (b) 39 (c) 12
5. 5.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) let (c) if (d) for
6. 6.⚡ What number does this code print?
   let coins = 5;
   coins = coins + 10;
   coins = coins - 15;
   console.log(coins);
7. 7.⚡ Where does console.log() show its output? (a) in the console (b) on the printer (c) on the title bar (d) in the address bar
8. 8.⚡ What does this code print? (Look at the quotes!)
   let x = "4";
   let y = 3;
   console.log(x + y); (a) 43 (b) 7 (c) Error
9. 9.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .html (c) .css (d) .jpg
10. 10.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 4;
    console.log(x + y); (a) Error (b) 24 (c) 6
11. 11.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 3;
    console.log(x + y); (a) 12 (b) 93 (c) Error
12. 12.⚡ What does JavaScript add to a web page? (a) the page title (b) only colours (c) the domain name (d) actions and changes
13. 13.⚡ What number does this code print?
    let a = 10;
    let b = 15;
    console.log(a + b);
14. 14.⚡ Which word makes a new variable? (a) give (b) let (c) make (d) put
15. 15.⚡ Which JavaScript word makes a new variable? (a) if (b) alert() (c) let (d) console.log()
16. 16.⚡ Which JavaScript word runs code when true? (a) for (b) console.log() (c) if (d) let
17. 17.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 6;
    console.log(x + y); (a) 16 (b) Error (c) 7
18. 18.⚡ What number does this code print?
    let books = 15;
    books = books + 16;
    books = books - 2;
    console.log(books);
19. 19.⚡ What does this code show?
    let name = "Zoya";
    alert("Hi, " + name + "!"); (a) Zoya (b) name (c) Hi, name! (d) Hi, Zoya!
20. 20.⚡ What does this code show?
    let name = "Zoya";
    console.log("Hi, " + name + "!"); (a) Hi, Zoya! (b) Hi, name! (c) Zoya (d) name
21. 21.⚡ What number does this code print?
    let a = 9;
    let b = 9;
    console.log(a * b);
22. 22.⚡ What does this code show?
    let name = "Arjun";
    console.log("Hi, " + name + "!"); (a) Hi, name! (b) Arjun (c) name (d) Hi, Arjun!
23. 23.⚡ What number does this code print?
    let score = 20;
    score = score + 7;
    score = score - 10;
    console.log(score);
24. 24.⚡ What does this code show?
    let name = "Aman";
    alert("Hi, " + name + "!"); (a) Hi, Aman! (b) Aman (c) name (d) Hi, name!
25. 25.⚡ What number does this code print?
    let a = 36;
    let b = 7;
    console.log(a - b);
26. 26.⚡ 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
27. 27.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 4;
    console.log(x + y); (a) 12 (b) 84 (c) Error
28. 28.⚡ What number does this code print?
    let a = 42;
    let b = 27;
    console.log(a - b);
29. 29.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 1;
    console.log(x + y); (a) 7 (b) Error (c) 61
30. 30.⚡ What number does this code print?
    let runs = 20;
    runs = runs + 10;
    runs = runs - 10;
    console.log(runs);
31. 31.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hi, " + name + "!"); (a) Hi, name! (b) Kabir (c) name (d) Hi, Kabir!
32. 32.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 3;
    console.log(x + y); (a) 10 (b) Error (c) 73
33. 33.⚡ What does this code show?
    let name = "Riya";
    alert("Hello, " + name + "!"); (a) Hello, Riya! (b) name (c) Riya (d) Hello, name!
34. 34.⚡ What number does this code print?
    let coins = 19;
    coins = coins + 5;
    coins = coins - 14;
    console.log(coins);
35. 35.⚡ What number does this code print?
    let a = 47;
    let b = 2;
    console.log(a - b);
36. 36.⚡ What does alert() show? (a) a new tab (b) a table (c) a picture (d) a pop-up box
37. 37.⚡ What number does this code print?
    let a = 47;
    let b = 25;
    console.log(a + b);
38. 38.⚡ What number does this code print?
    let books = 23;
    books = books + 11;
    books = books - 24;
    console.log(books);
39. 39.⚡ What number does this code print?
    let a = 38;
    let b = 9;
    console.log(a - b);
40. 40.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 2;
    console.log(x + y); (a) 12 (b) 3 (c) Error

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