Add Comments & fix Negative Number Case

src/main/java/task/TaskGeometricMean.java

@@ -2,18 +2,39 @@ package task;
 
 import java.util.Arrays;
 
+// This Task Calculate The Geometric Mean
+// The Geo-Mean is defined by :
+//         Geo-Mean = N-Root of (a1 * a2 * ... * an) , ai >=0
+//
 public class TaskGeometricMean extends TaskImpl {
 
     @Override
     public void execute() {
+        //Split the input values
         String[] stringArray = input.split(",");
+
+        // Parse the values
         double[] doubleArray = Arrays.stream(stringArray)
                 .mapToDouble(Double::parseDouble)
                 .toArray();
 
-        // Calculate the geometric mean
-        double product = Arrays.stream(doubleArray).reduce(1.0, (a, b) -> a * b);
-        double geometricMean = Math.pow(product, 1.0 / doubleArray.length);
-        result = String.valueOf(geometricMean);
+        // Check if all the values is poistive
+        boolean allPositive =Arrays.stream(doubleArray).allMatch((e)->e>0);
+
+        if(allPositive){
+            // Calculate the geometric mean
+
+            // Calculate P = (a1 * a2 * ... * an)
+            double product = Arrays.stream(doubleArray).reduce(1.0, (a, b) -> a * b);
+
+            // Calculate the Geo-Mean = N-Root of( P )
+            double geometricMean = Math.pow(product, 1.0 / doubleArray.length);
+
+            // Set tThe result
+            result = String.valueOf(geometricMean);
+        }else {
+            result="All The Array Values Should Be Positive";
+        }
+
     }
 }