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Suppose you have a JSON String, may be a web-service response and you want to create a Map out of it, where key should be the fields and value should be values of those fields e.g. if given JSON String is following :

{

"zip": "90210",

"city": "Beverly Hills"

"state": "CA"

"timeZone": "P"

}

then your HashMap should contain 4 mappings where keys are zip, city, state and timeZone, all of String type and corresponding values. 

One of the challenge you will face while using new Java 8 Date and time API, JSR-310 in existing Java application is the conversion between java.util.Date and java.time.LocalDate and other classes. Even though library has everything you would expect, it doesn't have a direct conversion method between old Date and new LocalDate. There is a reason for it, eventhough java.util.Date says its a date its not, becuase its just a millisecond value since midnight at the start of 1970 GMT. It's equivalent to Instant class in new Java Date API and that's why you have a direct conversion method between Date and Instant in Java 8. Anyway, its not hard to convert a java.util.Date to java.time.LocalDate in Java 8, in fact there are multiple ways which we will explore in this tutorial. 

Hello friends, we are here again today for another exciting topic to discuss. But, today we are not gonna discuss something which is related to Java or any other language or spring boot. Today we are gonna discuss something which is immensely practical and has the potential to land you very high-paying data science jobs.  Today we are gonna review a course that focuses on Machine Learning! Machine Learning is very important when we are considering data science interviews! So what's the wait? Let's start! On Educative.io, there is a great course called Grokking the Machine Learning Interview. It couldn't have come at a better moment, with machine learning expected to be a $3.6 billion business by 2025.

Problem : Given an integer i, find square root of it, without using Math.sqrt() method. Your method should return square root if given number is perfect square otherwise return floor(sqrt(x));

For example, 

Input i = 16

Output : 4

Input i = 17

Output : 4

This is very interesting problem and asked both freshers and experienced programmers. I have seen this question on many companies including ANZ, Barclays, and Citibank.

Problem : You have given an array of integer, check if the given array represents a binary max-heap data structure. In max heap every node is greater than all of its descendants. 

For example :

Input: array[] = {100, 25, 20, 17, 22, 12} 

Output: true

The given array represents below tree

100

/ \

25 20

/ \ /

17 22 12 

This binary tree follows max-heap property as every node is greater than all of its descendant.