JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 424 · 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 = "6";
   let y = 2;
   console.log(x + y); (a) Error (b) 8 (c) 62
2. 2.⚡ Which JavaScript word writes in the console? (a) for (b) alert() (c) if (d) console.log()
3. 3.⚡ Which tag holds JavaScript in a page? (a) <js> (b) <style> (c) <code> (d) <script>
4. 4.⚡ What does this code print? (Look at the quotes!)
   let x = "9";
   let y = 4;
   console.log(x + y); (a) 94 (b) Error (c) 13
5. 5.⚡ What does this code show?
   let name = "Zoya";
   console.log("Welcome, " + name + "!"); (a) Welcome, Zoya! (b) name (c) Zoya (d) Welcome, name!
6. 6.⚡ What number does this code print?
   let a = 42;
   let b = 29;
   console.log(a + b);
7. 7.⚡ Which JavaScript word runs code when true? (a) let (b) alert() (c) console.log() (d) if
8. 8.⚡ Which JavaScript word repeats code? (a) let (b) if (c) console.log() (d) for
9. 9.⚡ What does alert() show? (a) a new tab (b) a picture (c) a pop-up box (d) a table
10. 10.⚡ What number does this code print?
    let coins = 18;
    coins = coins + 5;
    coins = coins - 4;
    console.log(coins);
11. 11.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 2;
    console.log(x + y); (a) 4 (b) 22 (c) Error
12. 12.⚡ What number does this code print?
    let a = 8;
    let b = 4;
    console.log(a * b);
13. 13.⚡ What number does this code print?
    let runs = 18;
    runs = runs + 15;
    runs = runs - 9;
    console.log(runs);
14. 14.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 1;
    console.log(x + y); (a) 2 (b) 11 (c) Error
15. 15.⚡ Which JavaScript word shows a pop-up box? (a) for (b) let (c) console.log() (d) alert()
16. 16.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 3;
    console.log(x + y); (a) 12 (b) Error (c) 93
17. 17.⚡ 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
18. 18.⚡ What number does this code print?
    let a = 19;
    let b = 13;
    console.log(a + b);
19. 19.⚡ What number does this code print?
    let score = 26;
    score = score + 16;
    score = score - 9;
    console.log(score);
20. 20.⚡ What number does this code print?
    let books = 7;
    books = books + 13;
    books = books - 9;
    console.log(books);
21. 21.⚡ What number does this code print?
    let a = 54;
    let b = 39;
    console.log(a + b);
22. 22.⚡ What does this code show?
    let name = "Aman";
    console.log("Hi, " + name + "!"); (a) Hi, Aman! (b) Aman (c) Hi, name! (d) name
23. 23.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .css (c) .js (d) .jpg
24. 24.⚡ What number does this code print?
    let a = 7;
    let b = 25;
    console.log(a + b);
25. 25.⚡ What number does this code print?
    let marks = 15;
    marks = marks + 17;
    marks = marks - 2;
    console.log(marks);
26. 26.⚡ Where does console.log() show its output? (a) in the address bar (b) on the printer (c) in the console (d) on the title bar
27. 27.⚡ What number does this code print?
    let a = 3;
    let b = 9;
    console.log(a * b);
28. 28.⚡ What does this code show?
    let name = "Arjun";
    alert("Well done, " + name + "!"); (a) Well done, name! (b) name (c) Well done, Arjun! (d) Arjun
29. 29.⚡ What number does this code print?
    let books = 19;
    books = books + 12;
    books = books - 3;
    console.log(books);
30. 30.⚡ What number does this code print?
    let books = 26;
    books = books + 10;
    books = books - 2;
    console.log(books);
31. 31.⚡ What number does this code print?
    let a = 9;
    let b = 7;
    console.log(a * b);
32. 32.⚡ Which JavaScript word makes a new variable? (a) alert() (b) if (c) let (d) console.log()
33. 33.⚡ What does JavaScript add to a web page? (a) only colours (b) the page title (c) the domain name (d) actions and changes
34. 34.⚡ What number does this code print?
    let a = 50;
    let b = 1;
    console.log(a + b);
35. 35.⚡ What number does this code print?
    let coins = 28;
    coins = coins + 10;
    coins = coins - 12;
    console.log(coins);
36. 36.⚡ What number does this code print?
    let a = 42;
    let b = 15;
    console.log(a + b);
37. 37.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 6;
    console.log(x + y); (a) 7 (b) 16 (c) Error
38. 38.⚡ What number does this code print?
    let a = 6;
    let b = 4;
    console.log(a * b);
39. 39.⚡ Which word makes a new variable? (a) give (b) let (c) put (d) make
40. 40.⚡ What number does this code print?
    let a = 9;
    let b = 6;
    console.log(a * b);

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