Here is a solution to the Challenge utilizing the addYourselfToArray method given in the book. I have named the method addSelfToArray in the following code.
StockHolding.h
[code]#import <Foundation/Foundation.h>
@interface StockHolding : NSObject
{
float purchaseSharePrice;
float currentSharePrice;
int numberOfShares;
}
@property float purchaseSharePrice;
@property float currentSharePrice;
@property int numberOfShares;
- (float)costInDollars;
- (float)valueInDollars;
- (void)addSelfToArray:(NSMutableArray *)array;
@end[/code]
StockHolding.m
[code]#import “StockHolding.h”
@implementation StockHolding
@synthesize purchaseSharePrice, currentSharePrice, numberOfShares;
-
(float)costInDollars
{
return [self purchaseSharePrice] * [self numberOfShares];
} -
(float)valueInDollars
{
return [self currentSharePrice] * [self numberOfShares];
} -
(void)addSelfToArray:(NSMutableArray *)array;
{
return[array addObject:self];
}
@end[/code]
ForeignStockHolding.h
[code]#import “StockHolding.h”
@interface ForeignStockHolding : StockHolding
{
float conversionRate;
}
@property float conversionRate;
@end[/code]
ForeignStockHolding.m
[code]#import “ForeignStockHolding.h”
@implementation ForeignStockHolding
@synthesize conversionRate;
-
(float)costInDollars
{
float foreignCostInDollars = [super costInDollars];
return foreignCostInDollars * [self conversionRate];
} -
(float)valueInDollars
{
float foreignValueInDollars = [super valueInDollars];
return foreignValueInDollars * [self conversionRate];
}
@end[/code]
main.m
[code]int main(int argc, const char * argv[])
{
@autoreleasepool {
// Create instances of the class StockHolding
StockHolding *stockHolding1 = [[StockHolding alloc] init];
StockHolding *stockHolding2 = [[StockHolding alloc] init];
ForeignStockHolding *stockHolding3 = [[ForeignStockHolding alloc] init];
// Create a mutalbe Array to hold instances of the StockHolding and ForeignStockHolding Classes
NSMutableArray *stockHoldings = [[NSMutableArray alloc] init];
// Add variables and methods to each instance then add that instant to the stockHoldings array
[stockHolding1 setNumberOfShares:25];
[stockHolding1 setPurchaseSharePrice:2.30];
[stockHolding1 setCurrentSharePrice:4.50];
[stockHolding1 costInDollars];
[stockHolding1 valueInDollars];
[stockHolding1 addSelfToArray:stockHoldings];
[stockHolding2 setNumberOfShares:50];
[stockHolding2 setPurchaseSharePrice:2.30];
[stockHolding2 setCurrentSharePrice:4.50];
[stockHolding2 costInDollars];
[stockHolding2 valueInDollars];
[stockHolding2 addSelfToArray:stockHoldings];
[stockHolding3 setNumberOfShares:50];
[stockHolding3 setPurchaseSharePrice:2.30];
[stockHolding3 setCurrentSharePrice:4.50];
[stockHolding3 costInDollars];
[stockHolding3 valueInDollars];
[stockHolding3 setConversionRate:0.94];
[stockHolding3 addSelfToArray:stockHoldings];
// Itterate through the array printing out the values of each
for (StockHolding *n in stockHoldings) {
NSLog(@"\n Purchase Price: %.2f\n Current Price: %.2f\n Number Of Shares: %i\n Cost In Dollars: %.2f\n Value In Dollars: %.2f", [n purchaseSharePrice], [n currentSharePrice], [n numberOfShares], [n costInDollars], [n valueInDollars]);
}
}
return 0;
}[/code]
output
2012-03-31 23:43:36.172 StockTwo[2121:403]
Purchase Price: 2.30
Current Price: 4.50
Number Of Shares: 25
Cost In Dollars: 57.50
Value In Dollars: 112.50
2012-03-31 23:43:36.175 StockTwo[2121:403]
Purchase Price: 2.30
Current Price: 4.50
Number Of Shares: 50
Cost In Dollars: 115.00
Value In Dollars: 225.00
2012-03-31 23:43:36.175 StockTwo[2121:403]
Purchase Price: 2.30
Current Price: 4.50
Number Of Shares: 50
Cost In Dollars: 108.10
Value In Dollars: 211.50
