JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 441 · 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 = "1";
   let y = 4;
   console.log(x + y); (a) Error (b) 14 (c) 5
2. 2.⚡ What does this code show?
   let name = "Arjun";
   alert("Welcome, " + name + "!"); (a) Arjun (b) name (c) Welcome, name! (d) Welcome, Arjun!
3. 3.⚡ What number does this code print?
   let marks = 15;
   marks = marks + 18;
   marks = marks - 3;
   console.log(marks);
4. 4.⚡ What does JavaScript add to a web page? (a) only colours (b) the domain name (c) actions and changes (d) the page title
5. 5.⚡ What number does this code print?
   let a = 3;
   let b = 10;
   console.log(a * b);
6. 6.⚡ What number does this code print?
   let a = 2;
   let b = 6;
   console.log(a * b);
7. 7.⚡ What does this code print? (Look at the quotes!)
   let x = "8";
   let y = 1;
   console.log(x + y); (a) Error (b) 9 (c) 81
8. 8.⚡ What does this code show?
   let name = "Riya";
   console.log("Welcome, " + name + "!"); (a) Riya (b) Welcome, name! (c) Welcome, Riya! (d) name
9. 9.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .js (c) .jpg (d) .css
10. 10.⚡ What number does this code print?
    let runs = 19;
    runs = runs + 2;
    runs = runs - 1;
    console.log(runs);
11. 11.⚡ What number does this code print?
    let a = 45;
    let b = 37;
    console.log(a + b);
12. 12.⚡ Where does console.log() show its output? (a) in the console (b) on the title bar (c) on the printer (d) in the address bar
13. 13.⚡ Which JavaScript word writes in the console? (a) console.log() (b) alert() (c) if (d) for
14. 14.⚡ Which JavaScript word shows a pop-up box? (a) if (b) let (c) alert() (d) console.log()
15. 15.⚡ What number does this code print?
    let score = 29;
    score = score + 12;
    score = score - 17;
    console.log(score);
16. 16.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 6;
    console.log(x + y); (a) Error (b) 9 (c) 36
17. 17.⚡ Which JavaScript word repeats code? (a) if (b) alert() (c) let (d) for
18. 18.⚡ What number does this code print?
    let books = 19;
    books = books + 10;
    books = books - 27;
    console.log(books);
19. 19.⚡ Which JavaScript word runs code when true? (a) let (b) alert() (c) if (d) for
20. 20.⚡ What number does this code print?
    let a = 23;
    let b = 28;
    console.log(a + b);
21. 21.⚡ What number does this code print?
    let a = 4;
    let b = 7;
    console.log(a * b);
22. 22.⚡ Which JavaScript word makes a new variable? (a) alert() (b) let (c) for (d) console.log()
23. 23.⚡ What number does this code print?
    let a = 25;
    let b = 24;
    console.log(a - b);
24. 24.⚡ What does this code show?
    let name = "Aman";
    alert("Hello, " + name + "!"); (a) Hello, Aman! (b) Hello, name! (c) name (d) Aman
25. 25.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 1;
    console.log(x + y); (a) 41 (b) 5 (c) Error
26. 26.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <script> (c) <js> (d) <style>
27. 27.⚡ What does alert() show? (a) a table (b) a pop-up box (c) a picture (d) a new tab
28. 28.⚡ What does this code show?
    let name = "Meera";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) Hello, Meera! (c) Meera (d) name
29. 29.⚡ What number does this code print?
    let coins = 7;
    coins = coins + 6;
    coins = coins - 10;
    console.log(coins);
30. 30.⚡ What number does this code print?
    let a = 7;
    let b = 5;
    console.log(a * b);
31. 31.⚡ What does this code show?
    let name = "Zoya";
    console.log("Welcome, " + name + "!"); (a) Welcome, Zoya! (b) Welcome, name! (c) name (d) Zoya
32. 32.⚡ What number does this code print?
    let books = 7;
    books = books + 20;
    books = books - 26;
    console.log(books);
33. 33.⚡ What number does this code print?
    let a = 34;
    let b = 20;
    console.log(a - b);
34. 34.⚡ Which word makes a new variable? (a) let (b) make (c) put (d) give
35. 35.⚡ What number does this code print?
    let a = 12;
    let b = 9;
    console.log(a * b);
36. 36.⚡ What number does this code print?
    let a = 16;
    let b = 3;
    console.log(a - b);
37. 37.⚡ What number does this code print?
    let apples = 6;
    apples = apples + 10;
    apples = apples - 16;
    console.log(apples);
38. 38.⚡ What does this code show?
    let name = "Arjun";
    console.log("Hello, " + name + "!"); (a) Arjun (b) Hello, Arjun! (c) Hello, name! (d) name
39. 39.⚡ What does this code show?
    let name = "Kabir";
    alert("Hello, " + name + "!"); (a) Kabir (b) Hello, name! (c) name (d) Hello, Kabir!
40. 40.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 2;
    console.log(x + y); (a) 72 (b) Error (c) 9

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