JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 698 · 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 pop-up box (c) a picture (d) a new tab
2. 2.⚡ Which JavaScript word shows a pop-up box? (a) console.log() (b) for (c) let (d) alert()
3. 3.⚡ Which JavaScript word makes a new variable? (a) alert() (b) let (c) console.log() (d) for
4. 4.⚡ What does this code print? (Look at the quotes!)
   let x = "2";
   let y = 9;
   console.log(x + y); (a) 11 (b) Error (c) 29
5. 5.⚡ What does this code print? (Look at the quotes!)
   let x = "4";
   let y = 2;
   console.log(x + y); (a) 6 (b) Error (c) 42
6. 6.⚡ Which JavaScript word repeats code? (a) let (b) console.log() (c) for (d) if
7. 7.⚡ What does this code show?
   let name = "Arjun";
   console.log("Welcome, " + name + "!"); (a) Arjun (b) name (c) Welcome, Arjun! (d) Welcome, name!
8. 8.⚡ What does this code show?
   let name = "Riya";
   alert("Hello, " + name + "!"); (a) name (b) Hello, Riya! (c) Riya (d) Hello, name!
9. 9.⚡ What number does this code print?
   let score = 20;
   score = score + 17;
   score = score - 2;
   console.log(score);
10. 10.⚡ What number does this code print?
    let a = 15;
    let b = 3;
    console.log(a + b);
11. 11.⚡ Which JavaScript word runs code when true? (a) console.log() (b) alert() (c) for (d) if
12. 12.⚡ What does this code show?
    let name = "Kabir";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) Kabir (c) name (d) Hello, Kabir!
13. 13.⚡ What does this code show?
    let name = "Kabir";
    alert("Hi, " + name + "!"); (a) Kabir (b) Hi, name! (c) name (d) Hi, Kabir!
14. 14.⚡ What number does this code print?
    let a = 10;
    let b = 9;
    console.log(a * b);
15. 15.⚡ Which JavaScript word writes in the console? (a) if (b) let (c) alert() (d) console.log()
16. 16.⚡ What number does this code print?
    let a = 45;
    let b = 4;
    console.log(a + b);
17. 17.⚡ What number does this code print?
    let score = 29;
    score = score + 8;
    score = score - 18;
    console.log(score);
18. 18.⚡ Where does console.log() show its output? (a) on the printer (b) in the console (c) on the title bar (d) in the address bar
19. 19.⚡ What does JavaScript add to a web page? (a) only colours (b) the page title (c) actions and changes (d) the domain name
20. 20.⚡ What number does this code print?
    let score = 28;
    score = score + 16;
    score = score - 39;
    console.log(score);
21. 21.⚡ What does this code show?
    let name = "Aman";
    console.log("Well done, " + name + "!"); (a) Well done, Aman! (b) Aman (c) name (d) Well done, name!
22. 22.⚡ What number does this code print?
    let marks = 26;
    marks = marks + 16;
    marks = marks - 9;
    console.log(marks);
23. 23.⚡ What number does this code print?
    let a = 60;
    let b = 30;
    console.log(a + b);
24. 24.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 5;
    console.log(x + y); (a) 35 (b) 8 (c) Error
25. 25.⚡ What does this code show?
    let name = "Aman";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Aman (d) Hello, Aman!
26. 26.⚡ What does this code show?
    let name = "Meera";
    console.log("Hi, " + name + "!"); (a) name (b) Hi, Meera! (c) Hi, name! (d) Meera
27. 27.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 9;
    console.log(x + y); (a) Error (b) 99 (c) 18
28. 28.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 1;
    console.log(x + y); (a) 21 (b) Error (c) 3
29. 29.⚡ What number does this code print?
    let a = 3;
    let b = 3;
    console.log(a * b);
30. 30.⚡ What number does this code print?
    let books = 26;
    books = books + 17;
    books = books - 34;
    console.log(books);
31. 31.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 7;
    console.log(x + y); (a) Error (b) 13 (c) 67
32. 32.⚡ What number does this code print?
    let a = 46;
    let b = 17;
    console.log(a - b);
33. 33.⚡ What number does this code print?
    let a = 7;
    let b = 5;
    console.log(a - b);
34. 34.⚡ What does this code show?
    let name = "Riya";
    console.log("Welcome, " + name + "!"); (a) Welcome, Riya! (b) Welcome, name! (c) Riya (d) name
35. 35.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .js (c) .html (d) .jpg
36. 36.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <js> (c) <script> (d) <code>
37. 37.⚡ What number does this code print?
    let runs = 19;
    runs = runs + 4;
    runs = runs - 7;
    console.log(runs);
38. 38.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 3;
    console.log(x + y); (a) 83 (b) 11 (c) Error
39. 39.⚡ What does this code show?
    let name = "Meera";
    console.log("Well done, " + name + "!"); (a) Well done, Meera! (b) Meera (c) name (d) Well done, name!
40. 40.⚡ What number does this code print?
    let apples = 25;
    apples = apples + 5;
    apples = apples - 27;
    console.log(apples);

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