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POHow to retrieve and view the elements from the NSMutableArray
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  1. POHow to retrieve and view the elements from the NSMutableArray
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    copied!<p>I am trying some examples from the book "Objective C for Dummies". I tried to retrieve the elements with this code below but in vain. All are considered as Objects in the NSMutableArray. But I don't know how to retrieve the elements using the objects.</p> <h2>main.m</h2> <pre><code>#import &lt;Foundation/Foundation.h&gt; #import "BudObj.h" #import "Transaction.h" int main(int argc, char *argv[]) { Budget* europeBudget=[Budget new]; NSMutableArray *transactions=[[NSMutableArray alloc] initWithCapacity:10]; [europeBudget createBudget:1000.00 withExchangeRate:1.2500]; Transaction* aTransaction; aTransaction = [Transaction new]; for(int n=1;n&lt;2;n++){ aTransaction = [[Transaction alloc] init]; [aTransaction createTransaction:n*100 ofType:cash]; [transactions addObject:aTransaction]; [aTransaction release]; } int n=1; while (n&lt;3) { aTransaction = [[Transaction alloc]init]; [aTransaction createTransaction:n*100 ofType:credit]; [transactions addObject:aTransaction]; [aTransaction release]; n++; } do{ aTransaction = [[Transaction alloc]init]; [aTransaction createTransaction:n*100 ofType:cash]; [transactions addObject:aTransaction]; [aTransaction release]; n++; }while (n&lt;=3); NSLog(@"\nNumber of elements in an array:%i",[transactions count]); int c; c=[transactions count]; NSLog(@"\nThe Elements are:\n"); for(int i=0;i&lt;c;i++){ NSLog(@"%@",[transactions objectAtIndex:i]); } for(Transaction *aaTransaction in transactions){ switch ([aTransaction returnType]) { case cash: [europeBudget spendDollars:[aaTransaction returnAmount]]; break; case credit: [europeBudget changeForeignCurrency:[aaTransaction returnAmount]]; break; default: break; } } [transactions release]; [europeBudget release]; return 0; } </code></pre> <h2>BudObj.h</h2> <pre><code>#import &lt;Foundation/Foundation.h&gt; @interface Budget : NSObject { float exchangeRate; double budget; double exchangeTransaction; } - (void) createBudget: (double) aBudget withExchangeRate: (float) anExchangeRate; - (void) spendDollars: (double) dollars; - (void) changeForeignCurrency: (double) foreignCurrency; @end </code></pre> <h2>BudObj.m</h2> <pre><code>#import &lt;Foundation/Foundation.h&gt; #import "BudObj.h" #import "Transaction.h" @implementation Budget - (void) createBudget: (double) aBudget withExchangeRate: (float) anExchangeRate{ budget = aBudget; exchangeRate = anExchangeRate; } - (void) spendDollars:(double)dollars{ budget = budget - dollars; NSLog(@"Converting %0.2f US Dollars into Foreign Currency leaves $%0.2f",dollars,budget); } - (void) changeForeignCurrency:(double)foreignCurrency{ exchangeTransaction = foreignCurrency * exchangeRate; budget = budget - exchangeTransaction; NSLog(@"Charging %0.2f in Foreign Currency leaves $%0.2f",foreignCurrency,budget); } @end </code></pre> <h2>Transaction.h</h2> <pre><code>#import &lt;Cocoa/Cocoa.h&gt; typedef enum{cash,credit} transactionType; @interface Transaction : NSObject { transactionType type; double amount; } -(void)createTransaction:(double)theAmount ofType:(transactionType)theType; -(double)returnAmount; -(transactionType)returnType; @end </code></pre> <h2>Transaction.m</h2> <pre><code>#import "Transaction.h" @implementation Transaction -(void)createTransaction:(double)theAmount ofType:(transactionType)theType{ type=theType; amount=theAmount; } -(double)returnAmount{ return amount; } -(transactionType)returnType{ return type; } @end </code></pre> <h2>Output</h2> <pre><code>The Elements are: 2011-04-15 18:12:11.039 BudObj.m[2180:a0f] &lt;Transaction: 0x10010c950&gt; //Could not retreive the data from the array it's showing up some address 2011-04-15 18:12:11.039 BudObj.m[2180:a0f] &lt;Transaction: 0x100104fe0&gt; // 2011-04-15 18:12:11.040 BudObj.m[2180:a0f] &lt;Transaction: 0x100106c60&gt; // 2011-04-15 18:12:11.040 BudObj.m[2180:a0f] &lt;Transaction: 0x100106d00&gt; // 2011-04-15 18:12:11.041 BudObj.m[2180:a0f] Converting 100.00 US Dollars into Foreign Currency leaves $900.00 2011-04-15 18:12:11.041 BudObj.m[2180:a0f] Converting 100.00 US Dollars into Foreign Currency leaves $800.00 2011-04-15 18:12:11.041 BudObj.m[2180:a0f] Converting 200.00 US Dollars into Foreign Currency leaves $600.00 2011-04-15 18:12:11.042 BudObj.m[2180:a0f] Converting 300.00 US Dollars into Foreign Currency leaves $300.00 </code></pre>
 

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