JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 741 · 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 makes a new variable? (a) for (b) if (c) let (d) alert()
2. 2.⚡ 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
3. 3.⚡ What does this code print? (Look at the quotes!)
   let x = "1";
   let y = 1;
   console.log(x + y); (a) 2 (b) Error (c) 11
4. 4.⚡ What number does this code print?
   let a = 33;
   let b = 40;
   console.log(a + b);
5. 5.⚡ What number does this code print?
   let runs = 17;
   runs = runs + 11;
   runs = runs - 24;
   console.log(runs);
6. 6.⚡ Which JavaScript word repeats code? (a) if (b) for (c) alert() (d) console.log()
7. 7.⚡ What does this code show?
   let name = "Zoya";
   alert("Hello, " + name + "!"); (a) Hello, name! (b) Hello, Zoya! (c) name (d) Zoya
8. 8.⚡ What number does this code print?
   let apples = 5;
   apples = apples + 16;
   apples = apples - 6;
   console.log(apples);
9. 9.⚡ What does this code show?
   let name = "Meera";
   console.log("Well done, " + name + "!"); (a) name (b) Well done, Meera! (c) Well done, name! (d) Meera
10. 10.⚡ What does this code show?
    let name = "Arjun";
    alert("Hi, " + name + "!"); (a) name (b) Hi, name! (c) Hi, Arjun! (d) Arjun
11. 11.⚡ What number does this code print?
    let books = 19;
    books = books + 9;
    books = books - 5;
    console.log(books);
12. 12.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 1;
    console.log(x + y); (a) 81 (b) 9 (c) Error
13. 13.⚡ What does this code show?
    let name = "Arjun";
    alert("Welcome, " + name + "!"); (a) name (b) Welcome, Arjun! (c) Arjun (d) Welcome, name!
14. 14.⚡ Which word makes a new variable? (a) make (b) give (c) put (d) let
15. 15.⚡ Which JavaScript word writes in the console? (a) for (b) if (c) alert() (d) console.log()
16. 16.⚡ 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
17. 17.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 2;
    console.log(x + y); (a) 5 (b) Error (c) 32
18. 18.⚡ Which tag holds JavaScript in a page? (a) <js> (b) <code> (c) <script> (d) <style>
19. 19.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) for (c) let (d) if
20. 20.⚡ What does alert() show? (a) a pop-up box (b) a new tab (c) a table (d) a picture
21. 21.⚡ What number does this code print?
    let marks = 8;
    marks = marks + 19;
    marks = marks - 9;
    console.log(marks);
22. 22.⚡ What does this code show?
    let name = "Riya";
    alert("Welcome, " + name + "!"); (a) Welcome, name! (b) Riya (c) name (d) Welcome, Riya!
23. 23.⚡ What does JavaScript add to a web page? (a) the domain name (b) the page title (c) only colours (d) actions and changes
24. 24.⚡ What number does this code print?
    let a = 5;
    let b = 4;
    console.log(a * b);
25. 25.⚡ Which JavaScript word runs code when true? (a) alert() (b) let (c) if (d) console.log()
26. 26.⚡ What number does this code print?
    let a = 33;
    let b = 33;
    console.log(a + b);
27. 27.⚡ What number does this code print?
    let a = 2;
    let b = 5;
    console.log(a * b);
28. 28.⚡ What does this code show?
    let name = "Riya";
    alert("Hello, " + name + "!"); (a) Hello, Riya! (b) Riya (c) Hello, name! (d) name
29. 29.⚡ What number does this code print?
    let a = 11;
    let b = 12;
    console.log(a * b);
30. 30.⚡ What number does this code print?
    let runs = 26;
    runs = runs + 2;
    runs = runs - 12;
    console.log(runs);
31. 31.⚡ What does this code show?
    let name = "Riya";
    console.log("Hi, " + name + "!"); (a) Hi, name! (b) name (c) Hi, Riya! (d) Riya
32. 32.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 1;
    console.log(x + y); (a) 41 (b) Error (c) 5
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 1;
    console.log(x + y); (a) 51 (b) Error (c) 6
34. 34.⚡ What number does this code print?
    let a = 36;
    let b = 14;
    console.log(a + b);
35. 35.⚡ What number does this code print?
    let apples = 18;
    apples = apples + 11;
    apples = apples - 20;
    console.log(apples);
36. 36.⚡ What does this code show?
    let name = "Aman";
    console.log("Well done, " + name + "!"); (a) Well done, name! (b) name (c) Aman (d) Well done, Aman!
37. 37.⚡ A JavaScript file usually ends with which extension? (a) .jpg (b) .html (c) .js (d) .css
38. 38.⚡ What number does this code print?
    let score = 22;
    score = score + 19;
    score = score - 7;
    console.log(score);
39. 39.⚡ What number does this code print?
    let a = 13;
    let b = 38;
    console.log(a + b);
40. 40.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 9;
    console.log(x + y); (a) 99 (b) Error (c) 18

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