100+ JavaScript Code Snippets Every Developer Must Know!

Collection of 100+ JavaScript's most frequently asked coding questions and logical challenges. With this set of series, you will be able to sharpen your knowledge, gain exposure of using JavaScript ES6, Promises, Algorithms, Array, Object, Strings methods and much more.

If you want to be a good developer or want to crack any frontend interview - This book is a must to have 🙌🏼 !

The book is a must for every developer who wants to sharpen their knowledge, improve their analytical thinking, and logical reasoning, and above all give hands-on practice for the most important aspects of JavaScript.

The book covers all the major aspects of JavaScript like:

✅ Classes

✅ Arrays

✅ Objects

✅ Promises

✅ Async

✅ Maps

✅ Strings

✅ Algorithms

✅ Set

✅ Sorting

✅ Search

List of Questions Covered along with Code Snippets and Explanations!

1. How to define a class with properties and methods in JavaScript?
2. How to implement class inheritance in JavaScript?
3. How to find duplicate elements in a given array?
4. How to find the count of duplicates in an array?
5. How to check if a given number is an integer?
6. Explain the difference between Object.freeze() vs const?
7. How to Sort a Number Array?
8. Sort a given array of strings
9. How to find unique values in an array?
10. How to find unique values from an Array in sorted order?
11. Find maximum value in a numbered array?
12. Find minimum value in a numbered array?
13. Find the average of the numbers in the numbered array?
14. How can you uppercase the first character in a string array?
15. How to make a sentence out of the given string array?
16. How to check if an array contains any element of another array?
17. Given two strings, how can you check if the strings are anagram for each other?
18. How can you extract a few fields from the given JSON object and form a new array?
19. Filter the given object based on certain conditions and return the corresponding object?
20. Given an array of strings, reverse each word in the sentence?
21. How to check if an object is present in an Array or not?
22. How to empty an array?
23. What is IIFEs (Immediately Invoked Function Expressions)?
24. How do you sort and reverse an array without changing the original array?
25. Write a function to check if a given string is Palindrome or not?
26. How can you combine two Arrays into a third Array using spread operator?
27. How can you Insert an element at a specific index in an Array?
28. How can you Replace an element at a specific index in an Array?
29. How can you Delete an element at a specific index in an Array?
30. How can you delete a specific element?
31. How do you clone an Object?
32. How do you add an element at the beginning of an array?
33. How to remove an element from the end of the array?
34. How can you split a string into an Array?
35. How can you remove an element from the beginning of the array?
36. How can you add an element to an object?
37. How can you replace an existing element in an object?
38. How can you combine two objects?
39. How do you write a function which can take (x) number of parameters?
40. Convert the given number into the exact decimal points to the right side?
41. How do you return a character from a string at a specific index(2)?
42. How do you create an Array out of a given sentence?
43. How do you replace a given string in the string of arrays?
44. How do you write an add() function using javascript currying concept?
45. Implement a groupBy method in JavaScript?
46. Explain WeakSet in javascript with an example?
47. Explain WeakMap in javascript with an example?
48. Explain what is Object Destructuring with an example?
49. How can we generate a random alphanumeric string in JavaScript?
50. How can we call a function which logs a message after every 5 seconds?
51. How can we delay calling a function after 5 seconds?
52. Write a function that performs binary search on a sorted array?
53. How can we parse a given JSON object?
54. How do you check whether a string contains a substring?
55. How do I get query string values in javascript?
56. How to create and trigger events in javascript?
57. How to display the current date in javascript?
58. How do you compare time for two dates?
59. How do you check if a string starts with another string?
60. How do you remove whitespaces from a given string?
61. How do you assign default values to variables?
62. For a given function, count the number of parameters expected by a function?
63. Implement a method which generates 5 random numbers?
64. Implement a method which generates random numbers between 41 and 67 and sort them reverse?
65. How do you search a string for a pattern?
66. How to write an Object and implement multiple function chaining?
67. How do you determine whether an object is frozen or not?
68. How do you determine two values are the same or not using an object?
69. How do you copy properties from one object to another object?
70. How do you determine if an object is sealed or not?
71. How do you get an enumerable key and value pairs?
72. What is the main difference between Object.values and Object.entries method?
73. How can you get the list of keys of any object?
74. How do you encode an URL?
75. How do you define property on an Object constructor?
76. How can you call the constructor of a parent class?
77. How do you check whether an object can be extendable or not?
78. How do you prevent an object from extending?
79. How do you find the Vowels?
80. What are default values in destructuring assignment?
81. How do you swap variables in destructuring assignment?
82. How do you combine two or more arrays?
83. How to create a specific number of copies for a string?
84. What is the easiest way to convert an array to an object?
85. Verify that a function argument is a Number or not?
86. What is the easiest way to resize an Array?
87. What's the difference between a function expression and function declaration?
88. How to detect a mobile device with JavaScript?
89. How to fill static values in an array?
90. Why do we use The some() method in Arrays?
91. How to add 15 minutes to a JavaScript Date?
92. Explain JavaScript Promises with an example?
93. Which keyword can be used to deploy inheritance in ES6?
94. What is the difference between for..of and for..in?
95. How to set a property in localStorage?
96. Give a list of the various ways using which an HTML element can be accessed within a JavaScript code?
97. State the difference between Apply and Call?
98. What is the difference between undefined and not defined in JavaScript?
99. Explain Closure in JavaScript with an example?
100. How to calculate the length of an associative array using JavaScript?
101. Explain JavaScript promise.all with an example?
102. Explain Promise.race with an example?
103. Give an example of an Anonymous function?
104. What is Prototype Property? Explain with an Example.
105. Explain function hoisting with an example?
106. How to implement Bubble sort in JavaScript?
107. How to find prime numbers in an Array?
108. How to generate fibonacci series in JavaScript?