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POObjective-C: taking index of object in array
 

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  1. POObjective-C: taking index of object in array
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    <p>I'm new in Obj C programming, so i will start from beginning I have an array with some NSNumber and NSString elements, i want to replace NSString elems to NSNumber elems. I decide to make this with for in construction get to new NSMutableArray all elements value and to NSMutableIndexSet their indexes, but when i made this i faced with trouble, here it is, i show you my code and log.</p> <pre><code>NSArray *oneMoreStack = [program copy]; NSLog(@" stack=%@",oneMoreStack); NSLog(@" show me index ind=%@",[oneMoreStack indexOfObject:@"x"]); NSMutableIndexSet *myVarIndexesSet; NSMutableArray *myVarsArray; for (id myVarConst in oneMoreStack) { if([myVarConst isKindOfClass:[NSString class]]) { if([myVarConst isEqualToString:@"x"]){ [myVarsArray addObject:myVarConst]; NSLog(@"obj x=%@",myVarConst); [myVarIndexesSet addIndex:[oneMoreStack indexOfObject:myVarConst]]; NSLog(@"ind x=%@",[oneMoreStack indexOfObject:myVarConst]); } } </code></pre> <p>When i run it log show me this:</p> <pre><code>Calculator[6306:f803] stack=( x, 2, "+" ) Calculator[6306:f803] show me index ind=(null) Calculator[6306:f803] obj x=x Calculator[6306:f803] ind x=(null) then crash [NSMutableArray replaceObjectsAtIndexes:withObjects:]: index set cannot be nil </code></pre> <p>So, my question is why does <strong><code>[oneMoreStack indexOfObject:myVarConst]</code></strong> return <strong><code>null</code></strong>? How can i fix it? Thanks. I don't mention this code before because think problem is in getting indexes.</p> <p>after previous part of code goes this part:</p> <pre><code>[stack replaceObjectsAtIndexes:[myVarIndexesSet copy] withObjects:[myVarsArray copy]]; </code></pre> <p>after that crash with error report i mention previously. Thanks. </p>
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    1. USDima Deplov
    1. USDima Deplov
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    1. This table or related slice is empty.
 

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