JS:- https://www.w3resource.com/javascript-exercises/javascript-basic-exercises.php * https://career.guru99.com/top-85-javascript-interview-questions/https://github.com/nishant8BITS/123-Essential-JavaScript-Interview-Question. https://www.doppnet.com/10-advanced-javascript-interview-questions.htmlhttps://mindmajix.com/javascript-interview-questionshttps://www.quora.com/What-data-structures-should-I-know-as-a-full-stack-JavaScript-developerhttps://www.quora.com/What-are-the-most-important-JavaScript-concepts-to-know-for-a-job-interview

1. Call() & apply() & bind() => https://www.codementor.io/niladrisekhardutta/how-to-call-apply-and-bind-in-javascript-8i1jca6jp#call-or-functionprototypecall

https://www.w3schools.com/js/js_function_call.asp

2. Closures => http://javascriptissexy.com/understand-javascript-closures-with-ease/

3. Scope and context management => https://blog.kevinchisholm.com/javascript/difference-between-scope-and-context/

4. Performance => http://www.monitis.com/blog/30-tips-to-improve-javascript-performance/

5. Hoisting => https://www.w3schools.com/js/js_hoisting.asp

6. this => http://www.tutorialsteacher.com/javascript/this-keyword-in-javascript

7. Asynchronous Nature of JavaScript (Event loop) =>*(search with this heading) https://www.pluralsight.com/guides/front-end-javascript/introduction-to-asynchronous-javascript

https://stackoverflow.com/questions/21607692/understanding-the-event-loop

8. Object Oriented JavaScript (OOP in JavaScript) https://developer.mozilla.org/en-US/docs/Learn/JavaScript/Objects/Object-oriented_JS

9. promise https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promisehttps://coligo.io/javascript-promises-plain-simple/https://scotch.io/tutorials/javascript-promises-for-dummies

10)callback() https://www.w3schools.com/jquery/jquery_callback.asp

11)How to avoid callback(); http://callbackhell.com/http://www.dotnetfunda.com/interviews/show/10801/what-is-callback-hell-and-how-can-it-be-avoidedhttps://stackoverflow.com/questions/41290885/how-to-avoid-callback-hell

12. Difference b/w http and webscokets https://www.developerinsider.in/difference-between-http-and-http-2-0-websocket/

13. coding questions https://performancejs.com/post/hde6d32/The-Best-Frontend-JavaScript-Interview-Questions-%28written-by-a-Frontend-Engineer%29https://dev.to/maxpou/typical-javascript-interview-exercises-explained

14. Difference Between var, let, and const Keywords in JavaScript https://dzone.com/articles/javascript-difference-between-var-let-and-const-ke

15. what is the difference between cookie and session https://stackoverflow.com/questions/6339783/what-is-the-difference-between-sessions-and-cookies-in-php

16)https://www.sitepoint.com/shorthand-javascript-techniques/

17)difference between es5 and es6 javascript https://codeburst.io/es5-vs-es6-with-example-code-9901fa0136fchttps://www.quora.com/What-is-the-difference-between-JavaScript-and-ES6http://developmentr.com/javascript/2015/12/31/javascript-es6.html

18. var sttr = "chandra" ; console.log(sttr.split('cha').pop()); && console.log(sttr.substring(0,3)); && var nb ="chandu"; console.log(nb.substring(0,1));console.log(nb.substring(1,nb.length));

19. traingel , square , cirle , prime or not , fibanocci , assending , leapYearOrNot , dateFormat, Quick sort, Merge sort , Heap sort ,Insertion sort , Bubble sort , factorial , find the unique elements from two arrays , to move an array element from one position to another , to check whether an input is an array or not , o join all elements of the following array into a string , to find the most frequent item of an array , to remove duplicate items from an array , to perform a binary search , to compute the sum of each individual index value from the given arrays ,to find the difference of two arrays , to find the longest common starting substring in a set of strings , reverse a number & String , string is palindrome or not , Asending order and Desending order , first letter of each word of the string in upper case , Find the longest word within the string ,counts the number of vowels within the string , ake an array of numbers stored and find the second lowest and second greatest numbers , to find 1st January is being a Sunday between 2014 and 2050 , to get the extension of a filename , to replace every character in a given string with the character following it in the alphabet , to convert the letters of a given string in alphabetical order , to count the number of vowels in a given string. , to find the number of even digits in a given integer ,to convert a decimal number to binary, hexadecimal or octal number , to find the highest & lowest value in an array , to check to check whether a variable is numeric or not ,

 function primeNumOrNoT(num){if(num === 1){return false} else if(num === 2){return true} else{for(var x=2; x < num; x++ ){if(num % 2 === 0){return false} } return true} }; //================= 5 )- fibonaci series+++++++ the first two Fibonacci numbers are 0 and 1, and each subsequent number is the sum of the previous two. // Its recurrence relation is given by Fn = Fn-1 + Fn-2. function fibonaciSeries(num){var fibo = []; fibo[0] = 0; fibo[1] = 1; for(var i=2; i<= num ; i++){fibo[i] = fibo[i-1] + fibo[i-2]; console.log(fibo[i])} }; ////================= 6 )- factorial ++++++ function factorial(num){if(num === 0){return 1} return num * factorial(num - 1)} ////================= 7 )- PailndromeOrNot ++++++ function pailndromeOrNot(str){var pail= str.split("").reverse().join(""); if(str == pail){return true} return false} ////================= 8 )- Asending and Desending Order ++++++ function asendingOrder(array1){var asendingOrder = array1.sort(function(a,b){return a-b}); 

console.log(" --- asendingOrder --- " +asendingOrder );
}; function desendingOrder(array1){var desendingOrder = array1.sort(function(a,b){return b-a}); console.log(" --- desendingOrder --- " +desendingOrder );
}; ////================= 9 )- leapYearOrNot ++++++
function leapYearOrNot(year){x = (year % 100 === 0) ? (year % 400 === 0) : (year % 4 === 0); console.log(x)}; ////================= 10 )- dateFormat ++++++
function dateFormat(){var date = new Date(); console.log(date); var yyyy = date.getFullYear(); var mm = date.getMonth(); var dd = date.getDate(); var day = date.getDay(); var weeks = ["Mon","Tue" ,"Wed","Thu","Fri","Sat"]; console.log(mm + "/" + dd + "/" + yyyy); console.log("day -- "+weeks[day])}; ////================= 11 )- Find Unique num in two arrays ++++++
function findUniqueValuesInArray(arr1, arr2){let unique1 = arr1.filter((o) => arr2.indexOf(o)=== -1); let unique2 = arr2.filter((o) => arr1.indexOf(o) === -1); var unique = unique1.concat(unique2); console.log(unique)} ////================= 12 )- to move an array element from one position to another ++++++
function array_move(arr, old_index, new_index){if (new_index >= arr.length){var k = new_index - arr.length + 1; while (k--){arr.push(undefined)} } arr.splice(new_index, 0, arr.splice(old_index, 1)[0]); return arr}; ////================= 13 )- to check whether an input is an array or not ++++++
function isArray(arr1){if(toString.call(arr1) === "[object Array]" ){return true} return false}; ////================= 14 )- to join all elements of the following array into a string function toJoinArrayIntoString(arr1){var finalOutPut = arr1.toString(); var some = arr1.join("+"); console.log(some)} ////================= 15 )- to remove duplicate items from an array eg:- console.log(new Set(arr1));
function removeDuplicates(arr){let unique_array = [] for(let i = 0;i < arr.length; i++){if(unique_array.indexOf(arr[i]) == -1){unique_array.push(arr[i]) } } return unique_array }; //================= 16 )- Find 1st January is being a Sunday between 2014 and 2050. function findFirstSunday(startYear, endYear){console.log('--------------------'); for (var year = startYear; year <= endYear; year++){var d = new Date(year, 0, 1); if (d.getDay() === 0) console.log("1st January is being a Sunday " + year)} console.log('--------------------')}
//================= 17 )- reverse a number & String function reverse(input){var op = input.split("").reverse().join(""); console.log(op)} //================= 18 )- first letter of each word of the string in upper case function uppercase(str){var array1 = str.split(' '); var newarray1 = []; for(var x = 0; x < array1.length; x++){newarray1.push(array1[x].charAt(0).toUpperCase()+array1[x].slice(1))} return newarray1.join(' ')}

 document.writeln("<br/>navigator.appCodeName: " + navigator.appCodeName); document.writeln("<br/>navigator.appName: " + navigator.appName); document.writeln("<br/>navigator.appVersion: " + navigator.appVersion); document.writeln("<br/>navigator.cookieEnabled: " + navigator.cookieEnabled); document.writeln("<br/>navigator.language: " + navigator.language); document.writeln("<br/>navigator.userAgent: " + navigator.userAgent); document.writeln("<br/>navigator.platform: " + navigator.platform); document.writeln("<br/>navigator.onLine: " + navigator.onLine); function strPostion(){var arr1 = ["king", "queen", "minister", "quiz"]; var str = "" for (i = 0; i <= arr1.length; i++){console.log(arr1[i]); str = arr1[i] if (str.substring(0, 1) == "q"){console.log("---- " + str)} } } </script> </body> 

mongodb, documents , difference b/w sql and non sql , aggregation , sharding , replication , CRUD operations , why we use mongoose, what is the use of mongoose , Ad hoc queries , indexing , yield

https://www.mongodb.com/what-is-mongodbhttps://www.javatpoint.com/sql-vs-nosqlhttps://docs.mongodb.com/manual/aggregation/https://docs.mongodb.com/manual/sharding/https://docs.mongodb.com/manual/replication/https://docs.mongodb.com/manual/crud/https://stackoverflow.com/questions/18531696/why-do-we-need-what-advantages-to-use-mongoosehttps://code.tutsplus.com/articles/an-introduction-to-mongoose-for-mongodb-and-nodejs--cms-29527https://www.pcmag.com/encyclopedia/term/37486/ad-hoc-queryhttps://stackoverflow.com/questions/6576664/nosql-adhoc-queries-millions-of-rowshttps://www.simplilearn.com/indexing-and-aggregation-mongodb-tutorial-videohttps://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/yield

angular2 , component and modules,template , Directives, dependecy injection , routing , input and output , observers , how to pass the data in one component to another, lazyloading , forms using react.

https://angular.io/docshttps://www.tutorialspoint.com/angular2/angular2_components.htmhttps://www.tutorialspoint.com/angular2/angular2_modules.htmhttps://www.tutorialspoint.com/angular2/angular2_templates.htmhttps://www.tutorialspoint.com/angular2/angular2_directives.htmhttps://www.tutorialspoint.com/angular2/angular2_dependency_injection.htmhttps://scotch.io/tutorials/routing-angular-2-single-page-apps-with-the-component-routerhttps://www.sitepoint.com/angular-2-components-inputs-outputs/https://angular-2-training-book.rangle.io/v/v2.3/handout/observables/using_observables.htmlhttps://angularfirebase.com/lessons/sharing-data-between-angular-components-four-methods/https://toddmotto.com/passing-data-angular-2-components-inputhttps://stackoverflow.com/questions/34088209/how-to-pass-object-from-one-component-to-another-in-angular-2https://angular-2-training-book.rangle.io/v/v2.3/handout/modules/lazy-loading-module.htmlhttps://medium.com/aviabird/complete-angular2-guide-reactive-forms-in-depth-part-1-21a8e2428904