I want to compare two List of HashMaps in Java. I want to understand a way to compare them using lambda expressions and not with a nested for loop. Two List of HashMaps : productDetailsFromInputData; Sample Data : productDetailsFromApplication; Sample Data : Logic : I want to loop through the productDetailsFr…
Tag: lambda
argument mismatch; invalid functional descriptor for lambda expression
I am using the jdbi library like so: This try catch pattern is repeated a few times, with various different queries passed to the jdbi.withHandle method. Another example: The jdbi.withHandle method has this signature: I am trying to find a way to reduce the duplication around the try-catch, so that I can use …
Stack forEach expression to loop for difference between existing size and new one [closed]
Closed. This question needs details or clarity. It is not currently accepting answers. Want to improve this question? Add details and clarify the problem by editing this post. Closed 12 months ago. Improve this question I have a class with data member: The idea was to see if this forms a use case for lambda f…
how to keep track of mulitple closure variable in Java lambdas (or JVM language)?
Using Java, I am trying to find a clean way to accumulate multiple different value in a series of lambda. For a concrete example see this following piece of JS (typescript) code: I am not sure if there are existing Java Stream APIs for accumulate such a result. Maybe it’s not really possible and i shoul…
Java 8 edit stream elements
I need to filter and modify the values of the filtered object. The logic that must be filtered is given below. I have tried it like this. But how can we set the value of isUpdated = true using java 8? Answer Base on the logic given, findFirst should be used as you stop after the first instance is found.
field initialization with `val myVal: (long: Long) -> Unit)` what does it means?
I’m new to using Kotlin, so far seems amazing, however I don’t quite understand what’s going on here: So, here’s what I do understand: I am creating a class that contains a method which receives a MyObjectClass When I call onClick(someObject) I am actually indicating to call clickListe…
How to make a self-referencing lambda function that also references locals in Java?
I am trying to make a lambda function that references itself, and it is used as a callback for an asynchronous process, so I cannot use a loop. If I declare the function like so : the compiler tells me The local variable func may not have been initialized. If I write it that way instead : the compiler says
How would I turn this lambda function to a simple function?
I’m trying to understand lambda formatting in Java and could really use some help converting this function into a standard function to see how this works: Answer Start with the code to create an anonymous Callback object: Then paste in the right hand side of the -> lambda operator as call()’s m…
incompatible types: bad return type in lambda expression | void is not a functional interface
I am going through Java 8 Feature and using Jshell to explore it. I tried to run the below command: But it failed with the below error: I didn’t get exactly what’s the issue Consumer takes one argument and return nothing. Same I am doing here by passing 1 arg str and printing. So what’s the …
Getting local variable defined in the enclosing scope must be final or effective final
I am getting “local variable defined in the enclosing scope must be final or effective final” as highlighted below. I am not sure how to fix this out in lambda expression. Answer Try replacing this: by this: The entitlePackage will be effectively final. Also your code will be much easier to read a…