finally

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

 package com.zipcoder.payment;
 
+import java.sql.SQLOutput;
 import java.util.Arrays;
 
 public class PaymentPresenter {
 
-    private  Payment payment;
-    private int n;
+
     public String toString(Payment[] payments){
         if(payments.length == 0) {
 
 
     }
 
+
+    public String toStringByPayerName(Payment[] payments){
+        if(payments.length == 0){
+            return "";
+        }
+        else{
+            Arrays.sort(payments,new PaymentSortByPayer());
+            StringBuilder sb = new StringBuilder();
+                for(Payment p : payments){
+                System.out.println(p.getShortDescription());
+                sb.append(p.getShortDescription()+ "\n");
+            }
+            return sb.toString();
+        }
+
+    }
+
+    public String toStringById(Payment[] payments){
+        if(payments.length == 0){
+            return "";
+        }
+        else{
+            Arrays.sort(payments,new PaymentSortById());
+            StringBuilder sb = new StringBuilder();
+            for(Payment p: payments){
+                System.out.println(p.getShortDescription());
+                sb.append(p.getShortDescription());
+            }
+            return sb.toString();
+        }
+
+    }
+
 }

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

+package com.zipcoder.payment;
+
+import java.util.Comparator;
+
+public class PaymentSortById implements Comparator<Payment> {
+    public int compare(Payment o1, Payment o2) {
+        int n = o1.getId().compareTo(o2.getId());
+        return n;
+    }
+}

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

         Assert.assertEquals(expected, actual);
 
     }
+
+    @Test
+    public void toStringByPayerName(){
+
+        Payment[] payments = new Payment[2];
+        Payment paypal = new PayPal(4L, "Tamara Mowry", "tamara@mowry.com");
+        Payment 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);
+        Assert.assertEquals(expected, actual);
+
+    }
+
+    @Test
+    public void toStringById(){
+
+        Payment[] payments = new Payment[2];
+        Payment paypal = new PayPal(120L, "Tamara Mowry", "tamara@mowry.com");
+        Payment 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 Tamara Mowry tamara@mowry.com\n";
+
+        String actual = presenter.toString(payments);
+        Assert.assertEquals(expected, actual);
+
+
+    }
 }