Take into consideration hexadecimal numbers with floating point

MohamedBechir · MohamedBechir · commit 9ee9612b43e1 · 2020-05-25T20:39:57.000+01:00
diff --git a/src/main/java/com/conversions/HexadecimalToDecimal.java b/src/main/java/com/conversions/HexadecimalToDecimal.java
@@ -11,27 +11,58 @@ public class HexadecimalToDecimal {
      */
 	 public String hexToDecimal(String hexaStr) {
 		 String hexaNumbers = "0123456789ABCDEF";
-		 int m, result = 0;
+		 int m, result = 0, decimalNumberBefore = 0, power = -1;
+		 Double decimalNumberAfter = 0.0;
 		 char letter;
 		 String decimalStr;
 		 hexaStr = hexaStr.toUpperCase();
-		 
-		 for (int i = 0 ; i < hexaStr.length() ; i++) {
-				 /**
-				  * Letter will store the hexadecimal number as long as we loop through
-				  * the string
-				  */
-				 letter = hexaStr.charAt(i);
+		 int pointPosition = hexaStr.indexOf(".");
+		 /**
+		  * Check whether the number contains a float point or not
+		  */
+			if ( pointPosition == -1) {
+				 for (int i = 0 ; i < hexaStr.length() ; i++) {
+					 /**
+					  * Letter will store the hexadecimal number as long as we loop through
+					  * the string
+					  */
+					 letter = hexaStr.charAt(i);
 
-				 /**
-				  * m is the index of the number that we are looping through in the
-				  * hexaNumbers
-				  */
-				 m = hexaNumbers.indexOf(letter);
-				 result = 16*result + m;
-			 }
+					 /**
+					  * m is the index of the number that we are looping through in the
+					  * hexaNumbers
+					  */
+					 m = hexaNumbers.indexOf(letter);
+					 result = 16*result + m;
+				 }
+				  decimalStr = String.valueOf(result);
+
+			}
+				 else {
+					 for ( int i = 0 ;  i < pointPosition ; i++) {
+						 letter = hexaStr.charAt(i);
+						 m = hexaNumbers.indexOf(letter);
+						 decimalNumberBefore = 16*decimalNumberBefore + m;
+						}
+					 
+						String decimalNumberBeforeStr = String.valueOf(decimalNumberBefore);
+						
+						for ( int i = pointPosition+1 ;  i < hexaStr.length() ; i++) {
+							letter = hexaStr.charAt(i);
+							m = hexaNumbers.indexOf(letter);
+							decimalNumberAfter = (decimalNumberAfter + (Math.pow(16, power))*m);
+							power = power-1;
+						}
+						/**
+						 * Retrieve the decimal part of the result
+						 */
+						String decimalNumberAfterStr = String.valueOf(decimalNumberAfter);
+						int indexOfDecimal = decimalNumberAfterStr.indexOf(".");
+						decimalNumberAfterStr = decimalNumberAfterStr.substring(indexOfDecimal);
+						
+						decimalStr = decimalNumberBeforeStr + decimalNumberAfterStr;
+				 }
 			
-		  decimalStr = String.valueOf(result);
-		 return decimalStr ;
+					 return decimalStr ;
 	    }
 }
diff --git a/src/test/java/com/conversions/HexadecimalToDecimalTest.java b/src/test/java/com/conversions/HexadecimalToDecimalTest.java
@@ -10,6 +10,8 @@ class HexadecimalToDecimalTest {
 	void testHexadecimalToDecimalTest() {
 
 		HexadecimalToDecimal hexadecimalToDecimal = new HexadecimalToDecimal();
+		
+		//HexadecimaltTesting
         Assertions.assertEquals("171", hexadecimalToDecimal.hexToDecimal("AB"), "Incorrect Conversion");
         Assertions.assertEquals("5680077", hexadecimalToDecimal.hexToDecimal("56ABCD"), "Incorrect Conversion");
         Assertions.assertEquals("5174921", hexadecimalToDecimal.hexToDecimal("4ef689"), "Incorrect Conversion");
@@ -18,6 +20,13 @@ void testHexadecimalToDecimalTest() {
         //It returns -1 if you enter a wrong hexaDecimal
         Assertions.assertEquals("-1", hexadecimalToDecimal.hexToDecimal("K"), "Incorrect Conversion");
         
+        //Hexadecimal with floating point testing 
+        Assertions.assertEquals("10.6875", hexadecimalToDecimal.hexToDecimal("A.B"), "Incorrect Conversion");
+        Assertions.assertEquals("1386.737548828125", hexadecimalToDecimal.hexToDecimal("56A.BCD"), "Incorrect Conversion");
+        Assertions.assertEquals("78.9630279541015625", hexadecimalToDecimal.hexToDecimal("4e.f689"), "Incorrect Conversion");
+        Assertions.assertEquals("0.93359375", hexadecimalToDecimal.hexToDecimal(".EF"), "Incorrect Conversion");
+        Assertions.assertEquals("171.8044281005859375", hexadecimalToDecimal.hexToDecimal("AB.CDEF"), "Incorrect Conversion");
+
 	}
 
 }
