1	What are the possible ways to create objects in JavaScript
2	What is a prototype chain
3	What is the difference between Call, Apply and Bind
4	What is JSON and its common operations
5	What is the purpose of the array slice method
6	What is the purpose of the array splice method
7	What is the difference between slice and splice
8	How do you compare Object and Map
9	What is the difference between == and === operators
10	What are lambda expressions or arrow functions
11	What is a first class function
12	What is a first order function
13	What is a higher order function
14	What is a unary function
15	What is the currying function
16	What is a pure function
17	What is the purpose of the let keyword
18	What is the difference between let and var
19	What is the reason to choose the name let as a keyword
20	How do you redeclare variables in a switch block without an error
21	What is the Temporal Dead Zone
22	What is an IIFE (Immediately Invoked Function Expression)
23	How do you decode or encode a URL in JavaScript?
24	What is memoization
25	What is Hoisting
26	What are classes in ES6
27	What are closures
28	What are modules
29	Why do you need modules
30	What is scope in javascript
31	What is a service worker
32	How do you manipulate DOM using a service worker
33	How do you reuse information across service worker restarts
34	What is IndexedDB
35	What is web storage
36	What is a post message
37	What is a Cookie
38	Why do you need a Cookie
39	What are the options in a cookie
40	How do you delete a cookie
41	What are the differences between cookie, local storage and session storage
42	What is the main difference between localStorage and sessionStorage
43	How do you access web storage
44	What are the methods available on session storage
45	What is a storage event and its event handler
46	Why do you need web storage
47	How do you check web storage browser support
48	How do you check web workers browser support
49	Give an example of a web worker
50	What are the restrictions of web workers on DOM
51	What is a promise
52	Why do you need a promise
53	What are the three states of promise
54	What is a callback function
55	Why do we need callbacks
56	What is a callback hell
57	What are server-sent events
58	How do you receive server-sent event notifications
59	How do you check browser support for server-sent events
60	What are the events available for server sent events
61	What are the main rules of promise
62	What is callback in callback
63	What is promise chaining
64	What is promise.all
65	What is the purpose of the race method in promise
66	What is a strict mode in javascript
67	Why do you need strict mode
68	How do you declare strict mode
69	What is the purpose of double exclamation
70	What is the purpose of the delete operator
71	What is typeof operator
72	What is undefined property
73	What is null value
74	What is the difference between null and undefined
75	What is eval
76	What is the difference between window and document
77	How do you access history in javascript
78	How do you detect caps lock key turned on or not
79	What is isNaN
80	What are the differences between undeclared and undefined variables
81	What are global variables
82	What are the problems with global variables
83	What is NaN property
84	What is the purpose of isFinite function
85	What is an event flow
86	What is event bubbling
87	What is event capturing
88	How do you submit a form using JavaScript
89	How do you find operating system details
90	What is the difference between document load and DOMContentLoaded events
91	What is the difference between native, host and user objects
92	What are the tools or techniques used for debugging JavaScript code
93	What are the pros and cons of promises over callbacks
94	What is the difference between an attribute and a property
95	What is same-origin policy
96	What is the purpose of void 0
97	Is JavaScript a compiled or interpreted language
98	Is JavaScript a case-sensitive language
99	Is there any relation between Java and JavaScript
100	What are events
101	Who created javascript
102	What is the use of preventDefault method
103	What is the use of stopPropagation method
104	What are the steps involved in return false usage
105	What is BOM
106	What is the use of setTimeout
107	What is the use of setInterval
108	Why is JavaScript treated as Single threaded
109	What is an event delegation
110	What is ECMAScript
111	What is JSON
112	What are the syntax rules of JSON
113	What is the purpose JSON stringify
114	How do you parse JSON string
115	Why do you need JSON
116	What are PWAs
117	What is the purpose of clearTimeout method
118	What is the purpose of clearInterval method
119	How do you redirect new page in javascript
120	How do you check whether a string contains a substring
121	How do you validate an email in javascript
122	How do you get the current url with javascript
123	What are the various url properties of location object
124	How do get query string values in javascript
125	How do you check if a key exists in an object
126	How do you loop through or enumerate javascript object
127	How do you test for an empty object
128	What is an arguments object
129	How do you make first letter of the string in an uppercase
130	What are the pros and cons of for loops
131	How do you display the current date in javascript
132	How do you compare two date objects
133	How do you check if a string starts with another string
134	How do you trim a string in javascript
135	How do you add a key value pair in javascript
136	Is the !– notation represents a special operator
137	How do you assign default values to variables
138	How do you define multiline strings
139	What is an app shell model
140	Can we define properties for functions
141	What is the way to find the number of parameters expected by a function
142	What is a polyfill
143	What are break and continue statements
144	What are js labels
145	What are the benefits of keeping declarations at the top
146	What are the benefits of initializing variables
147	What are the recommendations to create new object
148	How do you define JSON arrays
149	How do you generate random integers
150	Can you write a random integers function to print integers within a range
151	What is tree shaking
152	What is the need of tree shaking
153	Is it recommended to use eval
154	What is a Regular Expression
155	What are the string methods that accept Regular expression
156	What are modifiers in regular expression

157	What are regular expression patterns
158	What is a RegExp object
159	How do you search a string for a pattern
160	What is the purpose of exec method
161	How do you change the style of a HTML element
162	What would be the result of 1+2+’3′
163	What is a debugger statement
164	What is the purpose of breakpoints in debugging
165	Can I use reserved words as identifiers
166	How do you detect a mobile browser
167	How do you detect a mobile browser without regexp
168	How do you get the image width and height using JS
169	How do you make synchronous HTTP request
170	How do you make asynchronous HTTP request
171	How do you convert date to another timezone in javascript
172	What are the properties used to get size of window
173	What is a conditional operator in javascript
174	Can you apply chaining on conditional operator
175	What are the ways to execute javascript after page load
176	What is the difference between proto and prototype
177	Can you give an example of when you really need a semicolon
178	What is a freeze method
179	What is the purpose of freeze method
180	Why do I need to use freeze method
181	How do you detect a browser language preference
182	How to convert string to title case with javascript
183	How do you detect javascript disabled in the page
184	What are various operators supported by javascript
185	What is a rest parameter
186	What happens if you do not use rest parameter as a last argument
187	What are the bitwise operators available in javascript
188	What is a spread operator
189	How do you determine whether object is frozen or not
190	How do you determine two values same or not using object
191	What is the purpose of using object is method
192	How do you copy properties from one object to other
193	What are the applications of assign method
194	What is a proxy object
195	What is the purpose of seal method
196	What are the applications of seal method
197	What are the differences between freeze and seal methods
198	How do you determine if an object is sealed or not
199	How do you get enumerable key and value pairs
200	What is the main difference between Object.values and Object.entries method
201	How can you get the list of keys of any object
202	How do you create an object with prototype
203	What is a WeakSet
204	What are the differences between WeakSet and Set
205	List down the collection of methods available on WeakSet
206	What is a WeakMap
207	What are the differences between WeakMap and Map
208	List down the collection of methods available on WeakMap
209	What is the purpose of uneval
210	How do you encode an URL
211	How do you decode an URL
212	How do you print the contents of web page
213	What is the difference between uneval and eval
214	What is an anonymous function
215	What is the precedence order between local and global variables
216	What are javascript accessors
217	How do you define property on Object constructor
218	What is the difference between get and defineProperty
219	What are the advantages of Getters and Setters
220	Can I add getters and setters using defineProperty method
221	What is the purpose of switch-case
222	What are the conventions to be followed for the usage of switch case
223	What are primitive data types
224	What are the different ways to access object properties
225	What are the function parameter rules
226	What is an error object
227	When you get a syntax error
228	What are the different error names from error object
229	What are the various statements in error handling
230	What are the two types of loops in javascript
231	What is nodejs
232	What is an Intl object
233	How do you perform language specific date and time formatting
234	What is an Iterator
235	How does synchronous iteration works
236	What is an event loop
237	What is call stack
238	What is an event queue
239	What is a decorator
240	What are the properties of Intl object
241	What is an Unary operator
242	How do you sort elements in an array
243	What is the purpose of compareFunction while sorting arrays
244	How do you reversing an array
245	How do you find min and max value in an array
246	How do you find min and max values without Math functions
247	What is an empty statement and purpose of it
248	How do you get metadata of a module
249	What is a comma operator
250	What is the advantage of a comma operator
251	What is typescript
252	What are the differences between javascript and typescript
253	What are the advantages of typescript over javascript
254	What is an object initializer
255	What is a constructor method
256	What happens if you write constructor more than once in a class
257	How do you call the constructor of a parent class
258	How do you get the prototype of an object
259	What happens If I pass string type for getPrototype method
260	How do you set prototype of one object to another
261	How do you check whether an object can be extendable or not
262	How do you prevent an object to extend
263	What are the different ways to make an object non-extensible
264	How do you define multiple properties on an object
265	What is MEAN in javascript
266	What Is Obfuscation in javascript
267	Why do you need Obfuscation
268	What is Minification
269	What are the advantages of minification
270	What are the differences between Obfuscation and Encryption
271	What are the common tools used for minification
272	How do you perform form validation using javascript
273	How do you perform form validation without javascript
274	What are the DOM methods available for constraint validation
275	What are the available constraint validation DOM properties
276	What are the list of validity properties
277	Give an example usage of rangeOverflow property
278	Is enums feature available in javascript
279	What is an enum
280	How do you list all properties of an object
281	How do you get property descriptors of an object
282	What are the attributes provided by a property descriptor
283	How do you extend classes
284	How do I modify the url without reloading the page
285	How do you check whether an array includes a particular value or not
286	How do you compare scalar arrays
287	How to get the value from get parameters
288	How do you print numbers with commas as thousand separators
289	What is the difference between java and javascript
290	Does JavaScript supports namespace
291	How do you declare namespace
292	How do you invoke javascript code in an iframe from parent page
293	How do get the timezone offset from date
294	How do you load CSS and JS files dynamically
295	What are the different methods to find HTML elements in DOM
296	What is jQuery
297	What is V8 JavaScript engine
298	Why do we call javascript as dynamic language
299	What is a void operator
300	How to set the cursor to wait
301	How do you create an infinite loop
302	Why do you need to avoid with statement
303	What is the output of the following for loops
304	List down some of the features of ES6
305	What is ES6
306	Can I redeclare let and const variables
307	Does the const variable make the value immutable
308	What are default parameters
309	What are template literals
310	How do you write multi-line strings in template literals
311	What are nesting templates
312	What are tagged templates
313	What are raw strings

314	What is destructuring assignment
315	What are default values in destructuring assignment
316	How do you swap variables in destructuring assignment
317	What are enhanced object literals
318	What are dynamic imports
319	What are the use cases for dynamic imports
320	What are typed arrays
321	What are the advantages of module loaders
322	What is collation
323	What is for…of statement
324	What is the output of below spread operator array
325	Is PostMessage secure
326	What are the problems with postmessage target origin as wildcard
327	How do you avoid receiving postMessages from attackers
328	Can I avoid using postMessages completely
329	Is postMessages synchronous
330	What paradigm is Javascript
331	What is the difference between internal and external javascript
332	Is JavaScript faster than server side script
333	How do you get the status of a checkbox
334	What is the purpose of double tilde operator
335	How do you convert character to ASCII code
336	What is ArrayBuffer
337	What is the output of below string expression
338	What is the purpose of Error object
339	What is the purpose of EvalError object
340	What are the list of cases error thrown from non-strict mode to strict mode
341	Do all objects have prototypes
342	What is the difference between a parameter and an argument
343	What is the purpose of some method in arrays
344	How do you combine two or more arrays
345	What is the difference between Shallow and Deep copy
346	How do you create specific number of copies of a string
347	How do you return all matching strings against a regular expression
348	How do you trim a string at the beginning or ending
349	What is the output of below console statement with unary operator
350	Does javascript uses mixins
351	What is a thunk function
352	What are asynchronous thunks
353	What is the output of below function calls
354	How to remove all line breaks from a string
355	What is the difference between reflow and repaint
356	What happens with negating an array
357	What happens if we add two arrays
358	What is the output of prepend additive operator on falsy values
359	How do you create self string using special characters
360	How do you remove falsy values from an array
361	How do you get unique values of an array
362	What is destructuring aliases
363	How do you map the array values without using map method
364	How do you empty an array
365	How do you round numbers to certain decimals
366	What is the easiest way to convert an array to an object
367	How do you create an array with some data
368	What are the placeholders from console object
369	Is it possible to add CSS to console messages
370	What is the purpose of dir method of console object
371	Is it possible to debug HTML elements in console
372	How do you display data in a tabular format using console object
373	How do you verify that an argument is a Number or not
374	How do you create copy to clipboard button
375	What is the shortcut to get timestamp
376	How do you flattening multi dimensional arrays
377	What is the easiest multi condition checking
378	How do you capture browser back button
379	How do you disable right click in the web page
380	What are wrapper objects
381	What is AJAX
382	What are the different ways to deal with Asynchronous Code
383	How to cancel a fetch request
384	What is web speech API
385	What is minimum timeout throttling
386	How do you implement zero timeout in modern browsers
387	What are tasks in event loop
388	What is microtask
389	What are different event loops
390	What is the purpose of queueMicrotask
391	How do you use javascript libraries in typescript file
392	What are the differences between promises and observables
393	What is heap
394	What is an event table
395	What is a microTask queue
396	What is the difference between shim and polyfill
397	How do you detect primitive or non primitive value type
398	What is babel
399	Is Node.js completely single threaded
400	What are the common use cases of observables
401	What is RxJS
402	What is the difference between Function constructor and function declaration
403	What is a Short circuit condition
404	What is the easiest way to resize an array
405	What is an observable
406	What is the difference between function and class declarations
407	What is an async function
408	How do you prevent promises swallowing errors
409	What is deno
410	How do you make an object iterable in javascript
411	What is a Proper Tail Call
412	How do you check an object is a promise or not
413	How to detect if a function is called as constructor
414	What are the differences between arguments object and rest parameter
415	What are the differences between spread operator and rest parameter
416	What are the different kinds of generators
417	What are the built-in iterables
418	What are the differences between for…of and for…in statements
419	How do you define instance and non-instance properties
420	What is the difference between isNaN and Number.isNaN?
421	How to invoke an IIFE without any extra brackets?
422	Is that possible to use expressions in switch cases?
423	What is the easiest way to ignore promise errors?
424	How do style the console output using CSS?
425	What is nullish coalescing operator (??)?
426	How do you group and nest console output?
427	What is the difference between dense and sparse arrays?
428	What are the different ways to create sparse arrays?
429	What is the difference between setTimeout, setImmediate and process.nextTick?
430	How do you reverse an array without modifying original array?
431	How do you create custom HTML element?
432	What is global execution context?
433	What is function execution context?
434	What is debouncing?
435	What is throttling?
436	What is optional chaining?
437	What is an environment record?
438	How to verify if a variable is an array?
439	What is pass by value and pass by reference?
440	What are the differences between primitives and non-primitives?
441	How do you create your own bind method using either call or apply method?
442	What are the differences between pure and impure functions?
443	What is referential transparency?
444	What are the possible side-effects in javascript?
445	What are compose and pipe functions?
446	What is module pattern?
447	What is Function Composition?
448	How to use await outside of async function prior to ES2022?
449	What is the purpose of the this keyword in JavaScript?
450	What are the uses of closures?
451	What are the phases of execution context?
452	What are the possible reasons for memory leaks?
453	What are the optimization techniques of V8 engine?
454	What are the examples of built-in higher order functions?
455	What are the benefits higher order functions?
456	How do you create polyfills for map, filter and reduce methods?
457	What is the difference between map and forEach functions?
458	Give an example of statements affected by automatic semicolon insertion?
459	What are the event phases of a browser?
460	What are the real world use cases of proxy?
461	What are hidden classes?
462	What is inline caching?
463	What are the different ways to execute external scripts?
464	What is Lexical Scope?
465	How to detect system dark mode in javascript?
466	What is the purpose of requestAnimationFrame method?
467	What is the difference between substring and substr methods?
468	How to find the number of parameters expected by a function?
469	What is globalThis, and what is the importance of it?
470	What are the array mutation methods?