Why should we use extends Mapper for Mapreduce code

Question

I am practicing MapReduce and going through some code. My question is, why do we use the extends keyword. i.e MyMapper extends Mapper. extends is meant for the keyword of inheritance in Java, then why we use it here?

Answer 1

The Mapper class belongs to package org.apache.hadoop.mapreduce and map function is a function of Mapper class so whenever you want to use any function of Mapper class you will be extending mapper class as parent class where MyMapper acts as a child class.