Adding objects to an NSmutableArray from a C Array - objective-c

Question

I have an NSmutable array and I am adding some strings present in the C array to it. By using this method
if (!self.arrayOfVariableNames) {
self.arrayOfVariableNames = [[NSMutableArray alloc] init];
for (int i = 0; i< cols; i++) {
[self.arrayOfVariableNames addObject:[NSString stringWithCString:cArrayOfVariableNames[i] encoding:NSUTF8StringEncoding ]];
}
}
else{
[self.arrayOfVariableNames removeAllObjects];
for (int i = 0; i< cols; i++) {
[self.arrayOfVariableNames addObject:[NSString stringWithCString:cArrayOfVariableNames[i] encoding:NSUTF8StringEncoding ]];
}
}
Does this method ensure that the objects in the NSmutableArray won't be deallocated when the C array is taken out of memory?

Answer 1

if this array arrayOfVariableNames is becoming Null, then the problem is with the initialisation of the array. Please try to use Lazy loading by doing this:
- (NSArray*)arrayOfVariableNames {
if (!_arrayOfVariableNames) {
_arrayOfVariableNames = [[NSMutableArray alloc] init]; //initialise the array if needed
}
return _arrayOfVariableNames; //else return the already initialized array
}
and please comment out this line in your code: self.arrayOfVariableNames = [[NSMutableArray alloc] init];
****EDIT****
Please find the update code in https://docs.google.com/file/d/0BybTW7Dwp2_vdHhQN1p1UzExdTA/edit?pli=1. Have a look at it.

Answer 2

Yes. NSArray retains anything in it.
But you should stop chaining your NSString creation and instead creat a string a line before adding it to the array. Then check for nil.
Only add it to the array if it is not nil.
Do code defensively.

Answer 3

arrayOfVariableNames will not change when the C array get deallocated.
Make sure that your arrayOfVariableNames variable is strong.
#property (nonatomic, strong) NSMutableArray *arrayOfVariableNames;
if (!self.arrayOfVariableNames)
{
self.arrayOfVariableNames = [[NSMutableArray alloc] init];
}
else
{
[self.arrayOfVariableNames removeAllObjects];
}
for (int i = 0; i< cols; i++)
{
NSString *tempString = [NSString stringWithCString:cArrayOfVariableNames[i] encoding:NSUTF8StringEncoding];
if([tempString length] > 0)
{
[self.arrayOfVariableNames addObject:tempString];
}
else
{
NSLog(#"string is empty");
}
}