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POObjective C:Cant understand the logic of looping
 

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  1. POObjective C:Cant understand the logic of looping
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    <p>I am new to Objective C. Currently, I am trying out some examples in Objective C. I am not getting the correct output. I could not understand the logic behind the correct output which I have included here.</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 createTransaction:n*100 ofType:credit]; [transactions addObject:aTransaction]; } int n=1; while (n&lt;3) { [aTransaction createTransaction:n*100 ofType:cash]; [transactions addObject:aTransaction]; n++; } do{ [aTransaction createTransaction:n*100 ofType:credit]; [transactions addObject:aTransaction]; n++; }while (n&lt;=3); for(Transaction *aaTransaction in transactions){ switch ([aTransaction returnType]) { case cash: [europeBudget spendDollars:[aaTransaction returnAmount]]; break; case credit: [europeBudget changeForeignCurrency:[aaTransaction returnAmount]]; break; default: break; } } return 0; } </code></pre> <hr> <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> <hr> <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> <hr> <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> <hr> <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> <hr> <h2>OUTPUT:</h2> <pre><code>2011-04-10 17:31:28.717 BudObj.m[3751:a0f] Charging 300.00 in Foreign Currency leaves $625.00 2011-04-10 17:31:28.719 BudObj.m[3751:a0f] Charging 300.00 in Foreign Currency leaves $250.00 2011-04-10 17:31:28.720 BudObj.m[3751:a0f] Charging 300.00 in Foreign Currency leaves $-125.00 2011-04-10 17:31:28.720 BudObj.m[3751:a0f] Charging 300.00 in Foreign Currency leaves $-500.00 </code></pre> <h2>But the expected output is</h2> <pre><code>Converting 100.00 US dollars into foreign currency leaves $900.00 Charging 100.00 in foreign currency leaves $775.00 Charging 200.00 in foreign currency leaves $525.00 Charging 300.00 in foreign currency leaves $150.00 Converting 100.00 US dollars into foreign currency leaves $1900.00 Charging 100.00 in foreign currency leaves $1750.00 </code></pre> <hr>
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    1. COIn future please take the time to format the code in your question appropriately (using the "{}" editor control).
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      1. USJohn Parker
    2. COYou've posted a ream of code and output here, but next to nothing about what your problem is. Do you need help finding a bug, or do you need the various forms of loops explained to you? Also, when posting code, it's a good idea to omit the code that you've commented out, GDB boilerplate, multiple blank spaces, etc.
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      1. USCaleb
    3. COSorry for the code and not questioning about it correctly. I could not understand how the objects are getting stored in the array through loops using the addObject method.
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