Create a new Foundation Command Line Tool called Stocks. Then create a class called BNRStockHolding to represent a stock that you have purchased. It will be a subclass of NSObject. For instance variables, it will have two floats named _purchaseSharePrice and _currentSharePrice and one int named _numberOfShares. Use properties to create accessor methods and instance variables. Create two other instance methods:

-​ ​(​f​l​o​a​t​)​c​o​s​t​I​n​D​o​l​l​a​r​s​;​ ​ ​/​/​ ​p​u​r​c​h​a​s​e​S​h​a​r​e​P​r​i​c​e​ ​*​ ​n​u​m​b​e​r​O​f​S​h​a​r​e​s​
-​ ​(​f​l​o​a​t​)​v​a​l​u​e​I​n​D​o​l​l​a​r​s​;​ ​/​/​ ​c​u​r​r​e​n​t​S​h​a​r​e​P​r​i​c​e​ ​*​ ​n​u​m​b​e​r​O​f​S​h​a​r​e​s​

In main(), fill an array with three instances of BNRStockHolding. Then iterate through the array printing out the value of each.

Figure 18.4  An array of BNRStockHolding objects