JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 465 · 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.⚡ Which JavaScript word runs code when true? (a) for (b) if (c) alert() (d) let
2. 2.⚡ What number does this code print?
   let a = 46;
   let b = 39;
   console.log(a - b);
3. 3.⚡ What does JavaScript add to a web page? (a) the page title (b) the domain name (c) actions and changes (d) only colours
4. 4.⚡ What does this code print? (Look at the quotes!)
   let x = "3";
   let y = 4;
   console.log(x + y); (a) Error (b) 7 (c) 34
5. 5.⚡ Which word makes a new variable? (a) let (b) put (c) make (d) give
6. 6.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .jpg (c) .css (d) .js
7. 7.⚡ What number does this code print?
   let a = 42;
   let b = 24;
   console.log(a + b);
8. 8.⚡ Which JavaScript word writes in the console? (a) alert() (b) let (c) console.log() (d) for
9. 9.⚡ Which JavaScript word makes a new variable? (a) let (b) console.log() (c) if (d) alert()
10. 10.⚡ Which JavaScript word repeats code? (a) for (b) let (c) console.log() (d) alert()
11. 11.⚡ 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
12. 12.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 2;
    console.log(x + y); (a) 8 (b) Error (c) 62
13. 13.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 1;
    console.log(x + y); (a) 9 (b) 81 (c) Error
14. 14.⚡ Which tag holds JavaScript in a page? (a) <js> (b) <style> (c) <code> (d) <script>
15. 15.⚡ What number does this code print?
    let runs = 24;
    runs = runs + 17;
    runs = runs - 41;
    console.log(runs);
16. 16.⚡ What does this code show?
    let name = "Riya";
    console.log("Hi, " + name + "!"); (a) Riya (b) Hi, name! (c) Hi, Riya! (d) name
17. 17.⚡ What number does this code print?
    let marks = 17;
    marks = marks + 6;
    marks = marks - 21;
    console.log(marks);
18. 18.⚡ What does this code show?
    let name = "Riya";
    alert("Well done, " + name + "!"); (a) Well done, Riya! (b) Well done, name! (c) Riya (d) name
19. 19.⚡ What does this code show?
    let name = "Kabir";
    alert("Hi, " + name + "!"); (a) Kabir (b) Hi, Kabir! (c) name (d) Hi, name!
20. 20.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) let (c) for (d) console.log()
21. 21.⚡ What number does this code print?
    let marks = 18;
    marks = marks + 8;
    marks = marks - 9;
    console.log(marks);
22. 22.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 7;
    console.log(x + y); (a) 13 (b) Error (c) 67
23. 23.⚡ What number does this code print?
    let score = 21;
    score = score + 16;
    score = score - 7;
    console.log(score);
24. 24.⚡ What does this code show?
    let name = "Meera";
    alert("Well done, " + name + "!"); (a) name (b) Meera (c) Well done, Meera! (d) Well done, name!
25. 25.⚡ What does this code show?
    let name = "Riya";
    alert("Hi, " + name + "!"); (a) name (b) Hi, name! (c) Hi, Riya! (d) Riya
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 6;
    console.log(x + y); (a) 12 (b) Error (c) 66
27. 27.⚡ What does this code show?
    let name = "Kabir";
    alert("Well done, " + name + "!"); (a) Well done, name! (b) Well done, Kabir! (c) name (d) Kabir
28. 28.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 6;
    console.log(x + y); (a) 8 (b) 26 (c) Error
29. 29.⚡ What number does this code print?
    let books = 6;
    books = books + 10;
    books = books - 3;
    console.log(books);
30. 30.⚡ What does this code show?
    let name = "Aman";
    alert("Welcome, " + name + "!"); (a) Aman (b) Welcome, Aman! (c) name (d) Welcome, name!
31. 31.⚡ What does this code show?
    let name = "Riya";
    alert("Welcome, " + name + "!"); (a) Welcome, Riya! (b) Welcome, name! (c) Riya (d) name
32. 32.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 4;
    console.log(x + y); (a) 8 (b) Error (c) 44
33. 33.⚡ What number does this code print?
    let a = 54;
    let b = 24;
    console.log(a - b);
34. 34.⚡ What number does this code print?
    let score = 5;
    score = score + 4;
    score = score - 8;
    console.log(score);
35. 35.⚡ What does this code show?
    let name = "Riya";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Riya (d) Hello, Riya!
36. 36.⚡ What number does this code print?
    let marks = 10;
    marks = marks + 17;
    marks = marks - 27;
    console.log(marks);
37. 37.⚡ What does alert() show? (a) a new tab (b) a table (c) a picture (d) a pop-up box
38. 38.⚡ What number does this code print?
    let a = 38;
    let b = 30;
    console.log(a - b);
39. 39.⚡ What number does this code print?
    let apples = 12;
    apples = apples + 19;
    apples = apples - 5;
    console.log(apples);
40. 40.⚡ What number does this code print?
    let a = 35;
    let b = 31;
    console.log(a - b);

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