JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 686 · 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.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .jpg (c) .html (d) .css
2. 2.⚡ Which JavaScript word makes a new variable? (a) if (b) console.log() (c) for (d) let
3. 3.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) console.log() (c) let (d) for
4. 4.⚡ 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
5. 5.⚡ What number does this code print?
   let score = 9;
   score = score + 19;
   score = score - 17;
   console.log(score);
6. 6.⚡ Which JavaScript word repeats code? (a) alert() (b) if (c) for (d) console.log()
7. 7.⚡ What does this code show?
   let name = "Aman";
   console.log("Hi, " + name + "!"); (a) Aman (b) Hi, name! (c) name (d) Hi, Aman!
8. 8.⚡ Which word makes a new variable? (a) make (b) let (c) give (d) put
9. 9.⚡ What does this code print? (Look at the quotes!)
   let x = "9";
   let y = 1;
   console.log(x + y); (a) 91 (b) Error (c) 10
10. 10.⚡ What does alert() show? (a) a picture (b) a table (c) a new tab (d) a pop-up box
11. 11.⚡ What number does this code print?
    let a = 5;
    let b = 5;
    console.log(a * b);
12. 12.⚡ Which JavaScript word runs code when true? (a) console.log() (b) for (c) let (d) if
13. 13.⚡ 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
14. 14.⚡ What does this code show?
    let name = "Aman";
    alert("Hi, " + name + "!"); (a) name (b) Aman (c) Hi, Aman! (d) Hi, name!
15. 15.⚡ What number does this code print?
    let apples = 6;
    apples = apples + 4;
    apples = apples - 5;
    console.log(apples);
16. 16.⚡ What number does this code print?
    let a = 57;
    let b = 28;
    console.log(a + b);
17. 17.⚡ What number does this code print?
    let apples = 15;
    apples = apples + 18;
    apples = apples - 27;
    console.log(apples);
18. 18.⚡ What number does this code print?
    let coins = 22;
    coins = coins + 9;
    coins = coins - 4;
    console.log(coins);
19. 19.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 4;
    console.log(x + y); (a) 13 (b) 94 (c) Error
20. 20.⚡ What does this code show?
    let name = "Aman";
    alert("Hello, " + name + "!"); (a) Hello, Aman! (b) name (c) Hello, name! (d) Aman
21. 21.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 1;
    console.log(x + y); (a) 31 (b) 4 (c) Error
22. 22.⚡ Which JavaScript word writes in the console? (a) for (b) alert() (c) let (d) console.log()
23. 23.⚡ What number does this code print?
    let a = 35;
    let b = 36;
    console.log(a + b);
24. 24.⚡ What does this code show?
    let name = "Zoya";
    console.log("Welcome, " + name + "!"); (a) name (b) Welcome, name! (c) Zoya (d) Welcome, Zoya!
25. 25.⚡ What number does this code print?
    let a = 22;
    let b = 10;
    console.log(a - b);
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 7;
    console.log(x + y); (a) Error (b) 97 (c) 16
27. 27.⚡ What number does this code print?
    let a = 59;
    let b = 4;
    console.log(a + b);
28. 28.⚡ What number does this code print?
    let a = 44;
    let b = 25;
    console.log(a - b);
29. 29.⚡ What number does this code print?
    let a = 39;
    let b = 18;
    console.log(a - b);
30. 30.⚡ What does this code show?
    let name = "Zoya";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) Hello, Zoya! (c) name (d) Zoya
31. 31.⚡ What does this code show?
    let name = "Zoya";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) Zoya (c) name (d) Hello, Zoya!
32. 32.⚡ What number does this code print?
    let a = 9;
    let b = 4;
    console.log(a * b);
33. 33.⚡ What does this code show?
    let name = "Arjun";
    alert("Welcome, " + name + "!"); (a) Arjun (b) name (c) Welcome, name! (d) Welcome, Arjun!
34. 34.⚡ What number does this code print?
    let a = 34;
    let b = 16;
    console.log(a - b);
35. 35.⚡ What number does this code print?
    let marks = 27;
    marks = marks + 2;
    marks = marks - 19;
    console.log(marks);
36. 36.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 7;
    console.log(x + y); (a) 77 (b) Error (c) 14
37. 37.⚡ What number does this code print?
    let books = 7;
    books = books + 12;
    books = books - 16;
    console.log(books);
38. 38.⚡ What number does this code print?
    let score = 5;
    score = score + 17;
    score = score - 20;
    console.log(score);
39. 39.⚡ What does this code show?
    let name = "Aman";
    alert("Well done, " + name + "!"); (a) name (b) Aman (c) Well done, Aman! (d) Well done, name!
40. 40.⚡ What does this code show?
    let name = "Kabir";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) name (c) Kabir (d) Welcome, Kabir!

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