DoubleFunction Interface is a part of the java.util.function package which is introduced in Java 8. It is an in-built Functional Interface. This function expect one double-valued argument as an input and produces a result. As it is a functional interface, it can be used assignment target for lambda expression or method reference. In this post, we are going to see several implementations of DoubleFunction Interface by using different examples.


DoubleFunction Interface in Java 8 with Examples...!!! Click To Tweet

Look at DoubleFunction Javadoc description below:


DoubleFunction Interface contains following method:


This method performs operation on the given double-valued argument and return the function result.

Lets understand above mentioned method thorough below example:

Example: ‘apply’ method

Java 8 DoubleFunction Interface is an absolute useful addition as part of ‘Functional Interfaces’ and can serve variety of purposes. It is quite powerful as it can be used as a higher order functions through lambda functions and above examples could help you to get better idea on how to implement it.

DoubleFunction Interface in Java 8 with Examples...!!! Click To Tweet

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  • Deepak Verma

    Deepak Verma is a Test Automation Consultant and Software development Engineer for more than 10 years. His mission is to help you become an In-demand full stack automation tester. He is also the founder of Techndeck, a blog and online coaching platform dedicated to helping you succeed with all the automation basics to advanced testing automation tricks.