// Helene Martin, CSE 142
// Reference semantics and String traversal
import java.util.*;

public class ReferenceSemantics {
	public static void main(String[] args) {
		int[] grades = {45, 68, 98, 100};
		// use Jeliot to visualize this (http://cs.joensuu.fi/jeliot/)
		int[] scores = grades;
		scores[2] = 12;
		
		// both are the same!  scores and grades hold a reference to the same array
		System.out.println(Arrays.toString(scores));  
		System.out.println(Arrays.toString(grades));
		
		System.out.println(reverse("cse142"));  		
	}
	
	// given a String, returns a String with letters in reverse order
	// can't work exactly like array reversal because Strings are immutable
	// build up a new string through concatenation
	// array			String
	// .length		.length()
	// [i]			.charAt(i)	
	public static String reverse(String initial) {
		String result = ""; // start with an empty string
		
		for (int i = 0; i < initial.length(); i++) {
			result = result + initial.charAt(initial.length() - i - 1); // cumulative sum pattern
		}
		
		return result;
	}
}