1 |
What are the possible ways to create objects in JavaScript |
2 |
What is 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 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 switch block without an error |
21 |
What is the Temporal Dead Zone |
22 |
What is 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 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 is 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 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 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 |
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 loop |
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 with in 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 available in 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 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 |
Give an example where do you really need 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 swtich 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 meta data 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 below for loops |
304 |
List down some of the features of ES6 |
305 |
What is ES6 |
306 |
Can I redeclare let and const variables |
307 |
Is const variable makes 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 rounding 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 are microtasks |
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? |
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