Commit arithmetic Subtraction double

src/arithmeticSubtraction.c

@@ -13,3 +13,8 @@ float* subtraction_float(float a, float b) {
     *result=a - b;
     return result;
 }
+double* subtraction_double(double a, double b) {
+    double* result= malloc(sizeof (double));
+    *result=a - b;
+    return result;
+}

src/arithmeticSubtraction.h

@@ -4,5 +4,6 @@
 
 int* subtraction_integer(int a, int b);
 float* subtraction_float(float a, float b);
+double* subtraction_double(double a, double b);
 
 #endif //THEADMIRALS_ARITHMETICSUBTRACTION_H

test/test_arithmeticSubtraction.c

@@ -21,4 +21,11 @@ void test_arithmeticSubtraction_subractionoftwonumberswithfloat(void) {
     result = subtraction_float(14, 7);
     TEST_ASSERT_EQUAL_FLOAT(expectedResult, *result);
 }
+void test_arithmeticSubtraction_subractionoftwonumberswithdouble(void) {
+    double expectedResult = 7;
+    double* result;
+    result = subtraction_double(14, 7);
+    TEST_ASSERT_EQUAL_DOUBLE (expectedResult, *result);
+}
+