Enumeration and removing a particular object from NSMutableArray

I'm having trouble removing items from my NSMutableArray. I'm extremely new to Objective-C, so please bear with me.

So far, I have the following: I'm trying to remove a line from the array if it has certain text inside. I cannot do this while fast-enumerating, so I'm trying to store the index, for removal after the enumeration has finished. However, I'm being told that this makes a pointer from an integer without a cast. Confused!

//First remove any previous Offending entry.
//Read hostfile into array.
NSString *hostFileOriginalString = [[NSString alloc] initWithContentsOfFile:@"/etc/hosts"];
NSMutableArray *hostFileOriginalArray = [[hostFileOriginalString componentsSepa开发者_如何学GoratedByString:@"\n"] mutableCopy];
NSInteger hostFileOffendingLocation;

//Use a for each loop to iterate through the array.
for (NSString *lineOfHosts in hostFileOriginalArray) {

    if ([lineOfHosts rangeOfString:@"Offending"].location != NSNotFound) {

    //Offending entry found, so remove it.
    //[hostFileOriginalArray removeObject:lineOfHosts];

    hostFileOffendingLocation = [hostFileOriginalArray indexOfObject:lineOfHosts];
    //NSLog(@"%@", hostFileOffendingLocation);
}

}
//Release the Array. 
[hostFileOriginalArray release];

//Remove offending entry from Array.
[hostFileOriginalArray removeObject:hostFileOffendingLocation];

My real question is why are you releasing your array before modifying it

try moving

[hostFileOriginalArray release];

to after

[hostFileOriginalArray removeObject:hostFileOffendingLocation];

You can do this without the loop by calling [hostFileOriginalArray removeObjectIdenticalTo:@"Offending"];

Note that it will remove multiple instances of the offending object, but that looks like what you want anyway. It will also do the operation in a fast way, without you having to worry about the implementation detail of which loop to use.

As a general rule (especially with the really commonly used objects like containers and NSString), check the class reference to see if Apple already has a way of doing what you want to do. It makes your code more readable to other Cocoa users (including future you), and reduces code maintenance- you're now leaving it up to Apple to add new technologies like Fast Enumeration to their code, and you get it for free when you link against new versions of the SDK.

Also, you should probably return hostFileOriginalArray at the end of the function, so it can do something useful- you can return it as an autoreleased object.

//Remove offending entry from Array.
[hostFileOriginalArray removeObjectAtIndex:hostFileOffendingLocation];

//Release the Array. 
[hostFileOriginalArray release];

you should have been getting compiler warnings... take a look at them, they are usually very helpful, I always try to have 0 warnings... that way I know where I have done something careless.