StreamsAPI-Tutorials/StreamExamples/IntPredicateExamples.java at main · CodeJamm/StreamsAPI-Tutorials · GitHub

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package StreamExamples;

import java.util.function.IntPredicate;

import java.util.stream.Collectors;

import java.util.stream.IntStream;

public class IntPredicateExamples

{

public static void main(String[] args)

{

//Java IntPredicate interface is a predicate of one int-valued argument.

//It can be considered an operator or function that returns a value either true or false based on certain evaluation on the argument int value.

//IntPredicate is a functional interface whose functional method is boolean test(int a).

IntPredicate isOdd = argument -> argument % 2 == 1;

//Use predicate directly

System.out.println(isOdd.test(9)); //true

System.out.println(isOdd.test(10)); //false

//Use predicate in filters

IntStream.range(1, 10).filter(isOdd).boxed()

.collect(Collectors.toList()).forEach(e->System.out.print(e+" "));

System.out.println();

//complex IntPredicate -> using logical AND, OR, etc...

IntPredicate isOddNumber = argument -> argument % 2 == 1;

IntStream.range(1, 20).filter(isOddNumber.and(IntPredicateExamples::isPrime))

.boxed()

.collect(Collectors.toList()).forEach(e->System.out.print(e+" "));

}

public static boolean isPrime(int i)

{

IntPredicate isDivisible = index -> i % index == 0;

return i > 1 && IntStream.range(2, i).noneMatch(isDivisible);

}

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