JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 518 · 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 number does this code print?
   let a = 7;
   let b = 9;
   console.log(a * b);
2. 2.⚡ What does this code print? (Look at the quotes!)
   let x = "8";
   let y = 3;
   console.log(x + y); (a) 11 (b) 83 (c) Error
3. 3.⚡ Which JavaScript word shows a pop-up box? (a) console.log() (b) for (c) if (d) alert()
4. 4.⚡ Which JavaScript word writes in the console? (a) console.log() (b) for (c) alert() (d) let
5. 5.⚡ 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
6. 6.⚡ Which JavaScript word repeats code? (a) if (b) console.log() (c) for (d) let
7. 7.⚡ What number does this code print?
   let a = 51;
   let b = 20;
   console.log(a - b);
8. 8.⚡ What does alert() show? (a) a pop-up box (b) a new tab (c) a picture (d) a table
9. 9.⚡ Which JavaScript word runs code when true? (a) console.log() (b) for (c) if (d) alert()
10. 10.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .html (c) .jpg (d) .js
11. 11.⚡ What does JavaScript add to a web page? (a) the page title (b) the domain name (c) only colours (d) actions and changes
12. 12.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <js> (c) <script> (d) <code>
13. 13.⚡ What does this code show?
    let name = "Aman";
    console.log("Well done, " + name + "!"); (a) name (b) Well done, name! (c) Aman (d) Well done, Aman!
14. 14.⚡ Which word makes a new variable? (a) put (b) give (c) make (d) let
15. 15.⚡ What number does this code print?
    let a = 3;
    let b = 5;
    console.log(a * b);
16. 16.⚡ What number does this code print?
    let a = 11;
    let b = 11;
    console.log(a - b);
17. 17.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 8;
    console.log(x + y); (a) Error (b) 48 (c) 12
18. 18.⚡ What does this code show?
    let name = "Aman";
    alert("Well done, " + name + "!"); (a) Aman (b) name (c) Well done, name! (d) Well done, Aman!
19. 19.⚡ What number does this code print?
    let a = 6;
    let b = 29;
    console.log(a + b);
20. 20.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 6;
    console.log(x + y); (a) Error (b) 12 (c) 66
21. 21.⚡ What does this code show?
    let name = "Meera";
    console.log("Welcome, " + name + "!"); (a) name (b) Meera (c) Welcome, Meera! (d) Welcome, name!
22. 22.⚡ Which JavaScript word makes a new variable? (a) let (b) for (c) console.log() (d) if
23. 23.⚡ What number does this code print?
    let a = 4;
    let b = 9;
    console.log(a * b);
24. 24.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 9;
    console.log(x + y); (a) Error (b) 18 (c) 99
25. 25.⚡ What number does this code print?
    let a = 36;
    let b = 20;
    console.log(a + b);
26. 26.⚡ What number does this code print?
    let a = 2;
    let b = 12;
    console.log(a * b);
27. 27.⚡ What number does this code print?
    let a = 5;
    let b = 6;
    console.log(a * b);
28. 28.⚡ What number does this code print?
    let coins = 28;
    coins = coins + 5;
    coins = coins - 11;
    console.log(coins);
29. 29.⚡ What number does this code print?
    let a = 28;
    let b = 18;
    console.log(a + b);
30. 30.⚡ What number does this code print?
    let a = 27;
    let b = 24;
    console.log(a - b);
31. 31.⚡ What number does this code print?
    let a = 31;
    let b = 1;
    console.log(a + b);
32. 32.⚡ What does this code show?
    let name = "Meera";
    alert("Hello, " + name + "!"); (a) Hello, Meera! (b) Hello, name! (c) Meera (d) name
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 7;
    console.log(x + y); (a) Error (b) 27 (c) 9
34. 34.⚡ What number does this code print?
    let a = 10;
    let b = 20;
    console.log(a + b);
35. 35.⚡ What number does this code print?
    let runs = 24;
    runs = runs + 9;
    runs = runs - 1;
    console.log(runs);
36. 36.⚡ What number does this code print?
    let marks = 15;
    marks = marks + 14;
    marks = marks - 4;
    console.log(marks);
37. 37.⚡ What does this code show?
    let name = "Riya";
    alert("Hi, " + name + "!"); (a) Hi, name! (b) Hi, Riya! (c) name (d) Riya
38. 38.⚡ What number does this code print?
    let a = 28;
    let b = 27;
    console.log(a - b);
39. 39.⚡ What number does this code print?
    let a = 11;
    let b = 10;
    console.log(a * b);
40. 40.⚡ What number does this code print?
    let a = 42;
    let b = 14;
    console.log(a + b);

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