Assert that the two lists have the same length. Done Create a list of all names and surnames. Done Is there any better way to do this ? or can the code be reduced? —> I need help. the output : [A, B, C, D, E, F, G, H, I, J, K, L] Answer I assume you don’t need a
Tag: java-stream
Get every nth element of nested lists using Java Streams
Here’s a function that will take a nested ArrayList allLists, an index nth, and return the nth element of every sublist. E.g. for allLists = {{1,2,3}, {4,5,6}, {7,8,9}}, nth = 1, the function will return {2,5,8} I’ve managed to get a version working where I can print it out: How to gather the resu…
Merging instances of objects in a list by attribute
I have an object Person which has firstName, lastName and email I have a list of Person where there are potentially multiple Persons of the same firstName and lastName and I want to merge these by their email address with a delimiter. i.e. Person A = Person B = And I want these to be merged into So as to
What is the difference between Stream.of and IntStream.range?
Please, consider this code: The output will be: Could anyone explain, why output of two streams are different? Answer Well, IntStream.range() returns a sequential ordered IntStream from startInclusive(inclusive) to endExclusive (exclusive) by an incremental step of 1, which means it’s already sorted. Si…
Two loops for into stream
I have some String method with two for and if: And I still try to change this implementation to some stream. Is it possible in this case? I’ve tried many options, but I have a problem with indexing (index++;) and then with filter in tableCells By.tagname. I think that is it not possible to change that f…
How to use java stream to convert a List of some class to a list/set of any one property of class?
I have a class I have a list of class student say, List<Student> students whose size is 100. I want to stream id of all the students and save it in a set Set<int>id, one easy way to do it is using a for loop, can someone please tell how the same can be implemented using java stream API. Answer
Java. Best way to split each element of List
How can I optimize this using streams ? Answer split returns the initial string if the delimiter is not found, so there is no need to test for “.” before performing the split:
Check if list elements are a continuous range of integers using java stream API [duplicate]
This question already has answers here: How can I check whether the numbers in the array list are sequential (3 answers) Closed 12 hours ago. Given var ns = List.of(1,2,3,4) How can one check if the list elements are consecutive using java stream API It can be done using the following loop: How can it be done…
Java Streams return throws error Unexpected return value
I am quite new to Java streams and I am trying to implement a method using the streams but when I try to return the value it’s throwing me the error Unexpected return value. I just wanted to know what am I doing wrong. Following is the return within the Arrays.stream value which is throwing the error: H…
How to reduce a limited stream (e.g. an ArrayList) from right in Java?
I would like to convert a list to a self-implemented linked list using reduce. I managed to do that in a reverse order: Output is I think to obtain result in the correct order, I may have to use something like foldRight or reduceRight in other languages. Does java provide anything similar, given that the stre…