find the difference between two lists in java code example

Example 1: php find differences between two arrays

<?php
$array1 = array("a" => "green", "red", "blue", "red");
$array2 = array("b" => "green", "yellow", "red");
$result = array_diff($array1, $array2);

print_r($result);
?>

Array
(
    [1] => blue
)

Example 2: in java how to compare two strings

class scratch{
    public static void main(String[] args) {
        String str1 = "Nyello";
        String str2 = "Hello";
        String str3 = "Hello";

        System.out.println( str1.equals(str2) ); //prints false
        System.out.println( str2.equals(str3) ); //prints true
    }
}