From f6a39f84bb36adad56c75ed77e411ab775d2cd54 Mon Sep 17 00:00:00 2001
From: iaforek <arkadiusz@jaworski.pl>
Date: Tue, 13 Jun 2017 22:29:27 +0100
Subject: [PATCH] BAEL-837 - Added jUnit test.

---
 .../maths/FloatingPointArithmetic.java        | 27 ++++++-----
 .../maths/FloatingPointArithmeticTest.java    | 45 +++++++++++++++++++
 2 files changed, 62 insertions(+), 10 deletions(-)
 create mode 100644 core-java/src/test/java/com/baeldung/maths/FloatingPointArithmeticTest.java

diff --git a/core-java/src/main/java/com/baeldung/maths/FloatingPointArithmetic.java b/core-java/src/main/java/com/baeldung/maths/FloatingPointArithmetic.java
index 9cdeeb5e81..4163adcf09 100644
--- a/core-java/src/main/java/com/baeldung/maths/FloatingPointArithmetic.java
+++ b/core-java/src/main/java/com/baeldung/maths/FloatingPointArithmetic.java
@@ -13,30 +13,37 @@ public class FloatingPointArithmetic {
         System.out.println("b =         " + b);
         System.out.println("c =         " + c);
         
-        double ab = a + b;
-        System.out.println("a + b =     " + ab);
+        double sum_ab = a + b;
+        System.out.println("a + b =     " + sum_ab);
         
         double abc =  a + b + c;
         System.out.println("a + b + c = " + abc);
         
-        double ac = a + c;
-        System.out.println("a + c =     " + ac);
+        double ab_c = sum_ab + c;
+        System.out.println("ab + c =    " + ab_c);
+        
+        double sum_ac = a + c;
+        System.out.println("a + c =     " + sum_ac);
         
         double acb = a + c + b;
         System.out.println("a + c + b = " + acb);
         
-        double ac_b = ac + b;
+        double ac_b = sum_ac + b;
         System.out.println("ac + b =    " + ac_b);
         
+        double ab = 18.1;
+        double ac = 34.67;
+        double sum_ab_c = ab + c;
+        double sum_ac_b = ac + b;
+        System.out.println("ab + c =    " + sum_ab_c);
+        System.out.println("ac + b =    " + sum_ac_b);
+        
         BigDecimal d = new BigDecimal(String.valueOf(a));
         BigDecimal e = new BigDecimal(String.valueOf(b));
         BigDecimal f = new BigDecimal(String.valueOf(c));
         
-        BigDecimal def;
-        BigDecimal dfe;
-        
-        def = d.add(e).add(f);
-        dfe = d.add(f).add(e);
+        BigDecimal def = d.add(e).add(f);
+        BigDecimal dfe = d.add(f).add(e);
         
         System.out.println("d + e + f = " + def);
         System.out.println("d + f + e = " + dfe);
diff --git a/core-java/src/test/java/com/baeldung/maths/FloatingPointArithmeticTest.java b/core-java/src/test/java/com/baeldung/maths/FloatingPointArithmeticTest.java
new file mode 100644
index 0000000000..2066f13c6d
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/maths/FloatingPointArithmeticTest.java
@@ -0,0 +1,45 @@
+package com.baeldung.maths;
+
+import java.math.BigDecimal;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class FloatingPointArithmeticTest {
+
+    @Test
+    public void givenDecimalNumbers_whenAddedTogether_thenGetExpectedResult() {
+        double a = 13.22;
+        double b = 4.88;
+        double c = 21.45;
+        double result = 39.55;
+        
+        double abc = a + b + c;
+        double acb = a + c + b;
+        
+        Assert.assertEquals(result, abc, 0);
+        Assert.assertNotEquals(result, acb, 0);
+        
+        double ab = 18.1;
+        double ac = 34.67;
+        
+        double ab_c = ab + c;
+        double ac_b = ac + b;
+        
+        Assert.assertEquals(result, ab_c, 0);
+        Assert.assertNotEquals(result, ac_b, 0);
+        
+        BigDecimal d = new BigDecimal(String.valueOf(a));
+        BigDecimal e = new BigDecimal(String.valueOf(b));
+        BigDecimal f = new BigDecimal(String.valueOf(c));
+        BigDecimal sum = new BigDecimal("39.55");
+        
+        BigDecimal def = d.add(e).add(f);
+        BigDecimal dfe = d.add(f).add(e);
+        
+        Assert.assertEquals(0, def.compareTo(sum));
+        Assert.assertEquals(0, dfe.compareTo(sum));
+        
+        Assert.assertNotEquals(0, sum.compareTo(new BigDecimal(String.valueOf(acb))));
+    }
+}