JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 386 · 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 = "7";
   let y = 1;
   console.log(x + y); (a) 8 (b) Error (c) 71
2. 2.⚡ Which JavaScript word writes in the console? (a) if (b) let (c) console.log() (d) for
3. 3.⚡ Which JavaScript word shows a pop-up box? (a) if (b) for (c) console.log() (d) alert()
4. 4.⚡ What does JavaScript add to a web page? (a) only colours (b) actions and changes (c) the domain name (d) the page title
5. 5.⚡ What number does this code print?
   let a = 11;
   let b = 5;
   console.log(a * b);
6. 6.⚡ What does this code show?
   let name = "Meera";
   alert("Hello, " + name + "!"); (a) Hello, name! (b) Hello, Meera! (c) name (d) Meera
7. 7.⚡ What number does this code print?
   let books = 11;
   books = books + 8;
   books = books - 4;
   console.log(books);
8. 8.⚡ What number does this code print?
   let a = 30;
   let b = 37;
   console.log(a + b);
9. 9.⚡ What does this code print? (Look at the quotes!)
   let x = "2";
   let y = 9;
   console.log(x + y); (a) Error (b) 11 (c) 29
10. 10.⚡ Where does console.log() show its output? (a) in the address bar (b) on the title bar (c) on the printer (d) in the console
11. 11.⚡ What number does this code print?
    let coins = 26;
    coins = coins + 9;
    coins = coins - 17;
    console.log(coins);
12. 12.⚡ What does this code show?
    let name = "Arjun";
    console.log("Hi, " + name + "!"); (a) Hi, name! (b) Arjun (c) name (d) Hi, Arjun!
13. 13.⚡ What does this code show?
    let name = "Arjun";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) Arjun (c) Hello, Arjun! (d) name
14. 14.⚡ What does this code show?
    let name = "Riya";
    console.log("Welcome, " + name + "!"); (a) name (b) Welcome, name! (c) Riya (d) Welcome, Riya!
15. 15.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 2;
    console.log(x + y); (a) 10 (b) Error (c) 82
16. 16.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .html (c) .js (d) .jpg
17. 17.⚡ Which tag holds JavaScript in a page? (a) <script> (b) <style> (c) <js> (d) <code>
18. 18.⚡ What number does this code print?
    let score = 16;
    score = score + 8;
    score = score - 4;
    console.log(score);
19. 19.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 7;
    console.log(x + y); (a) 10 (b) Error (c) 37
20. 20.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 8;
    console.log(x + y); (a) 28 (b) 10 (c) Error
21. 21.⚡ What does this code show?
    let name = "Aman";
    console.log("Well done, " + name + "!"); (a) name (b) Aman (c) Well done, name! (d) Well done, Aman!
22. 22.⚡ Which JavaScript word repeats code? (a) for (b) console.log() (c) let (d) alert()
23. 23.⚡ What does this code show?
    let name = "Meera";
    alert("Welcome, " + name + "!"); (a) Welcome, name! (b) Welcome, Meera! (c) name (d) Meera
24. 24.⚡ What number does this code print?
    let a = 25;
    let b = 11;
    console.log(a - b);
25. 25.⚡ Which JavaScript word makes a new variable? (a) alert() (b) for (c) let (d) if
26. 26.⚡ What number does this code print?
    let a = 28;
    let b = 10;
    console.log(a - b);
27. 27.⚡ What number does this code print?
    let apples = 25;
    apples = apples + 19;
    apples = apples - 41;
    console.log(apples);
28. 28.⚡ Which word makes a new variable? (a) give (b) let (c) put (d) make
29. 29.⚡ What number does this code print?
    let marks = 24;
    marks = marks + 9;
    marks = marks - 23;
    console.log(marks);
30. 30.⚡ What number does this code print?
    let a = 40;
    let b = 11;
    console.log(a - b);
31. 31.⚡ What number does this code print?
    let apples = 30;
    apples = apples + 4;
    apples = apples - 31;
    console.log(apples);
32. 32.⚡ What number does this code print?
    let runs = 5;
    runs = runs + 18;
    runs = runs - 1;
    console.log(runs);
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 4;
    console.log(x + y); (a) Error (b) 34 (c) 7
34. 34.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 7;
    console.log(x + y); (a) Error (b) 9 (c) 27
35. 35.⚡ What does alert() show? (a) a table (b) a pop-up box (c) a picture (d) a new tab
36. 36.⚡ What does this code show?
    let name = "Zoya";
    alert("Hello, " + name + "!"); (a) Zoya (b) Hello, Zoya! (c) Hello, name! (d) name
37. 37.⚡ What number does this code print?
    let a = 21;
    let b = 16;
    console.log(a - b);
38. 38.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 6;
    console.log(x + y); (a) 9 (b) Error (c) 36
39. 39.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 9;
    console.log(x + y); (a) 18 (b) Error (c) 99
40. 40.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 1;
    console.log(x + y); (a) Error (b) 91 (c) 10

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