JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 402 · 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 alert() show? (a) a table (b) a new tab (c) a pop-up box (d) a picture
2. 2.⚡ What number does this code print?
   let a = 40;
   let b = 5;
   console.log(a + b);
3. 3.⚡ What number does this code print?
   let a = 60;
   let b = 6;
   console.log(a + b);
4. 4.⚡ What number does this code print?
   let marks = 17;
   marks = marks + 10;
   marks = marks - 21;
   console.log(marks);
5. 5.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .css (c) .jpg (d) .js
6. 6.⚡ What number does this code print?
   let a = 5;
   let b = 39;
   console.log(a + b);
7. 7.⚡ Which JavaScript word writes in the console? (a) alert() (b) console.log() (c) if (d) for
8. 8.⚡ What number does this code print?
   let a = 45;
   let b = 39;
   console.log(a - b);
9. 9.⚡ 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
10. 10.⚡ What number does this code print?
    let books = 17;
    books = books + 12;
    books = books - 19;
    console.log(books);
11. 11.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 7;
    console.log(x + y); (a) Error (b) 8 (c) 17
12. 12.⚡ Which JavaScript word shows a pop-up box? (a) for (b) let (c) alert() (d) if
13. 13.⚡ What does this code show?
    let name = "Kabir";
    alert("Hello, " + name + "!"); (a) Kabir (b) Hello, Kabir! (c) Hello, name! (d) name
14. 14.⚡ What does this code show?
    let name = "Meera";
    console.log("Hello, " + name + "!"); (a) name (b) Hello, name! (c) Hello, Meera! (d) Meera
15. 15.⚡ What number does this code print?
    let runs = 23;
    runs = runs + 6;
    runs = runs - 8;
    console.log(runs);
16. 16.⚡ What number does this code print?
    let runs = 17;
    runs = runs + 4;
    runs = runs - 5;
    console.log(runs);
17. 17.⚡ 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
18. 18.⚡ What number does this code print?
    let coins = 12;
    coins = coins + 11;
    coins = coins - 23;
    console.log(coins);
19. 19.⚡ Which JavaScript word runs code when true? (a) let (b) for (c) console.log() (d) if
20. 20.⚡ Which word makes a new variable? (a) let (b) give (c) put (d) make
21. 21.⚡ What does this code show?
    let name = "Riya";
    console.log("Hi, " + name + "!"); (a) Hi, name! (b) Riya (c) name (d) Hi, Riya!
22. 22.⚡ Which JavaScript word makes a new variable? (a) alert() (b) let (c) console.log() (d) if
23. 23.⚡ What does this code show?
    let name = "Riya";
    alert("Welcome, " + name + "!"); (a) Riya (b) name (c) Welcome, name! (d) Welcome, Riya!
24. 24.⚡ What number does this code print?
    let coins = 10;
    coins = coins + 4;
    coins = coins - 4;
    console.log(coins);
25. 25.⚡ What number does this code print?
    let coins = 13;
    coins = coins + 12;
    coins = coins - 20;
    console.log(coins);
26. 26.⚡ What number does this code print?
    let score = 18;
    score = score + 10;
    score = score - 22;
    console.log(score);
27. 27.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 4;
    console.log(x + y); (a) 44 (b) 8 (c) Error
28. 28.⚡ What number does this code print?
    let runs = 8;
    runs = runs + 2;
    runs = runs - 5;
    console.log(runs);
29. 29.⚡ What number does this code print?
    let a = 10;
    let b = 11;
    console.log(a * b);
30. 30.⚡ What does this code show?
    let name = "Aman";
    console.log("Hello, " + name + "!"); (a) name (b) Aman (c) Hello, name! (d) Hello, Aman!
31. 31.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 5;
    console.log(x + y); (a) 55 (b) Error (c) 10
32. 32.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 1;
    console.log(x + y); (a) 11 (b) Error (c) 2
33. 33.⚡ What number does this code print?
    let books = 16;
    books = books + 14;
    books = books - 1;
    console.log(books);
34. 34.⚡ What number does this code print?
    let score = 8;
    score = score + 15;
    score = score - 12;
    console.log(score);
35. 35.⚡ What number does this code print?
    let score = 18;
    score = score + 7;
    score = score - 7;
    console.log(score);
36. 36.⚡ What number does this code print?
    let books = 21;
    books = books + 19;
    books = books - 2;
    console.log(books);
37. 37.⚡ What number does this code print?
    let books = 15;
    books = books + 11;
    books = books - 14;
    console.log(books);
38. 38.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 8;
    console.log(x + y); (a) Error (b) 14 (c) 68
39. 39.⚡ What does this code show?
    let name = "Zoya";
    alert("Welcome, " + name + "!"); (a) Welcome, name! (b) Welcome, Zoya! (c) name (d) Zoya
40. 40.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 9;
    console.log(x + y); (a) 15 (b) Error (c) 69

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