November 19, 2021

Let user handle null case, using functional programming in modern java

When pass an object to a function, then there is a scenario which always arises. That, the passed object could be null. And, we have to write logic to react to that null-condition. And, generally that logic is hard-coded in the function. And, there are times as a user I feel that, instead of throwing an exception […]

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October 28, 2020

java.util.function.IntFunction implementation using modern java

IntFunction is a functional interface, it takes an int and returns a reference type. This reference type can be specified by using generic type specification. We can implement it in different ways. Implement using a regular class. private class IntFuncImpl implements IntFunction<Integer>{ @Override public Integer apply(final int intValue) { return Integer.valueOf(intValue); } } Implement using […]

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October 28, 2020

Double Unary Operator Implementation using modern java

DoubleUnaryOperator is a functional interface that lives in java.util.function package. It has one function applyAsDouble, which takes a double and returns a double. It is called an UnaryOperator, because it performs it’s action on a single argument. And, that single argument is of double type that’s why it has Double in it’s name. We can implement […]

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October 10, 2020

java.util.function.IntBinaryOperator implementation in modern Java

In this blog post, I will show you the different ways to implement java.util.function.IntBinaryOperator. You can watch my youtube video, where I code these implementation. A Regular Class.. private class RegularImpl implements IntBinaryOperator{ @Override public int applyAsInt(final int firstIntValue, final int secondIntValue){ return firstIntValue > secondIntValue ? firstIntValue : secondIntValue; } } Implementation using a […]

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October 7, 2020

java.util.function.Function implementation using modern java.

In this blog, I will show you the different ways to implement java.util.function.Function interface in modern java. You can watch me code these examples on youtube. First implementation is using implementation keyword in a regular class private class FuncImpl implements Function<Person, Integer>{ @Override public Integer apply(final Person person){ return person.getAge(); } } Second way uses anonymous class for implementation. […]

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September 11, 2020

Sum Of Integer Array : How To Do Functional Programming In Java

We can use functional Programming in Java to calculate sum of an int array. You can watch my live coding video to see how it is done. Traditional Way :- int sum = 0; for(int intValue : ints) sum += intValue; Functional Programming Way 1 :- Arrays.stream(ints).sum(); Functional Programming Way 2 :- Arrays.stream(ints).reduce(0, Integer::sum); Functional […]

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September 11, 2020

Currying : How To Do functional Programming In Java

One of the key identifiers of functional programming is Currying. Since Java 8, the new features were added, allows us to do this operation. What is currying? currying is a name assigned to ‘half initialized functions’. A Curried function has some of the parameters fixed while other parameters will be passed by the users. We […]

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February 10, 2019

How to implement java.util.function.DoubleToLongFunction

java.util.function.DoubleToLongFunction is a primitive specialization of Other Functional Interfaces. What it means is , we can get the same functionality using other functional interfaces, but they are going to be slow. Because of boxing and unboxing. If you are dealing with Double and Long wrapper objects then use other functional interface. So, this functional interface is […]

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