JavaLambdaExpression.java

// https://www.hackerrank.com/challenges/java-lambda-expressions/problem

public class JavaLambdaExpression {
 private interface PerformOperation {
 boolean check(int number);
 }

 private static class MyMath {
 public static PerformOperation isOdd() {
 return (int a) -> a % 2 != 0;
 }

 public static PerformOperation isPrime() {
 return (int number) -> {
 if(number == 1) return false;

 for (int index = 2 ; index * index <= number ; index++) {
 if (number % index == 0) {
 return false;
 }
 }
 return true;
 };
 }

 public static PerformOperation isPalindrome() {
 return (int a) -> {
 String number = a + "";
 String reverse = new StringBuilder(number).reverse().toString();
 return number.equals(reverse);
 };
 }
 }
}