Question

Out of convenience often when I have a method where I need
to reuse the same local variable for different purposes I tend do something like this:

NSMutableArray *mutArray = [NSMutableArray arrayWithObjects: @"one", @"two", nil];
[self fooWithArray:mutArray];

mutArray = [NSMutableArray arrayWithObjects: @"three", @"four", nil];
[self barWithArray:mutArray];

//and

MyClass *myClass = [[MyClass alloc]initWithString:@"one"];
self.oneClass = myClass;
[myClass release];

myClass = [[MyClass alloc]initWithString:@"two"];
self.twoClass = myClass;
[myClass release];

Memory-wise, is this the right thing to do ?
Is this code prone to memory leaks ?

Answer 1

You don’t have to assign objects to variables before using them. The only reason I can see for doing that would be verbosity, but it’s not required.

You could get away with:

[self fooWithArray:[NSMutableArray arrayWithObjects: @"one", @"two", nil]];
[self barWithArray:[NSMutableArray arrayWithObjects: @"three", @"four", nil]];

//and

self.oneClass = [[[MyClass alloc]initWithString:@"one"] autorelease];
self.twoClass = [[[MyClass alloc]initWithString:@"two"] autorelease];