finished

src/main/java/com/zipcoder/payment/PaymentPresenter.java

@@ -1,16 +1,41 @@
 package com.zipcoder.payment;
 
+		import java.util.ArrayList;
 		import java.util.Arrays;
 		import java.util.Comparator;
 
 public class PaymentPresenter {
 
+
 	public String toString(Payments[] payments) {
 		StringBuilder sb = new StringBuilder();
 		Arrays.sort(payments);
 		for (int i = 0; i < payments.length; i++) {
-			payments[i].getShortDescription().toString();
+			sb.append(payments[i].getShortDescription()+"\n");
+		}
+		return sb.toString();
+	}
+
+
+	public String toStringByPayerName(Payments[] payments) {
+		StringBuilder sb = new StringBuilder();
+		Arrays.sort(payments, new PaymentSortByPayer());
+		for (int i = 0; i < payments.length; i++) {
+			sb.append(payments[i].getShortDescription()+"\n");
 		}
-		return null;
+		return sb.toString();
+
+	}
+
+	public String toStringById(Payments[] payments) {
+
+		Comparator<Payments> id = ((o1, o2) -> o1.getID().compareTo(o2.getID()));
+				StringBuilder sb = new StringBuilder();
+		Arrays.sort(payments, id);
+		for (int i = 0; i < payments.length; i++) {
+			sb.append(payments[i].getShortDescription()+"\n");
+		}
+		return sb.toString();
+
+	}
 	}
-}

src/main/java/com/zipcoder/payment/PaymentSortByPayer.java

@@ -9,4 +9,5 @@ public class PaymentSortByPayer implements Comparator<Payments>{
 
 		return o1.getPayerName().compareTo(o2.getPayerName());
 	}
+
 }

src/main/java/com/zipcoder/payment/Paypal.java

@@ -40,7 +40,7 @@ public class Paypal implements Payments {
 
 	@Override
 	public String getShortDescription() {
-		return "Paypal "+ payerName+ email;
+		return "Paypal "+ payerName +" "+email;
 	}
 
 	@Override

src/test/java/com/zipcoder/payment/PaymentPresenterTest.java

@@ -6,15 +6,21 @@ import org.junit.Before;
 import org.junit.Test;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 
 public class PaymentPresenterTest {
 
+	Check check;
+	Paypal paypal;
+
+
+	PaymentPresenter presenter;
 
 	@Before
 	public void setup() {
 		StringBuilder sb = new StringBuilder();
-	}
 
+	}
 
 
 	@Test
@@ -31,8 +37,53 @@ public class PaymentPresenterTest {
 
 	@Test
 
-	public void multiplesToStringById() {
+	public void toStringByPayerName() {
+		Payments[] payments = new Payments[2];
+		Payments paypal = new Paypal(4L, "Tia Mowry", "tia@mowry.com");
+		Payments check = new Check(81L, "Tia Mowry", "11432543", "134344551");
+
+		payments[0] = paypal;
+		payments[1] = check;
+
+		PaymentPresenter presenter = new PaymentPresenter();
+		String expected = "Check Tia Mowry ***4551\nPaypal Tia Mowry tia@mowry.com\n";
+
+		String actual = presenter.toString(payments);
+		assertEquals(expected, actual);
+
 
 	}
 
+	@Test
+	public void toStringByPayer() {
+		Payments[] payments = new Payments[2];
+		Payments paypal = new Paypal(4L, "Tamara Mowry", "tamara@mowry.com");
+		Payments check = new Check(81L, "Tia Mowry", "11432543", "134344551");
+
+		payments[0] = paypal;
+		payments[1] = check;
+
+		PaymentPresenter presenter = new PaymentPresenter();
+		String expected = "Paypal Tamara Mowry tamara@mowry.com\nCheck Tia Mowry ***4551\n";
+
+		String actual = presenter.toStringByPayerName(payments);
+		assertEquals(expected, actual);
+	}
+
+	@Test
+	public void toStringById(){
+		Payments[] payments = new Payments[2];
+		Payments paypal = new Paypal(81L, "Tamara Mowry", "tamara@mowry.com");
+		Payments check = new Check(120L, "Tia Mowry", "11432543", "134344551");
+
+		payments[0] = paypal;
+		payments[1] = check;
+
+		PaymentPresenter presenter = new PaymentPresenter();
+		String expected = "Paypal Tamara Mowry tamara@mowry.com\nCheck Tia Mowry ***4551\n";
+
+		String actual = presenter.toStringById(payments);
+		assertEquals(expected, actual);
+	}
+
 }

src/test/java/com/zipcoder/payment/PaypalTest.java

@@ -51,6 +51,8 @@ public class PaypalTest {
 
 		String expect = "Paypal Tia Mowry tia@mowry.com";
 		String actual = test.getShortDescription();
+		Assert.assertEquals(expect, actual);
+
 	}
 
 	@Test