来自NSArray的NSMutableArray

Question

i have the following code and i want to use NSMutable arrays instead of NSArray could you tell me how to load the NSMutable array, as the current method does not work.

-(void) whatever{
NSData *htmlData = [[NSString stringWithContentsOfURL:[NSURL URLWithString: @"http://www.objectgraph.com/contact.html"]] dataUsingEncoding:NSUTF8StringEncoding];
TFHpple *xpathParser = [[TFHpple alloc] initWithHTMLData:htmlData];
NSArray *titles  = [xpathParser search:@"//h3"]; // get the page title - this is xpath     notation
TFHppleElement *title = [titles objectAtIndex:0];
NSString *myTitles = [title content];

NSArray *articles  = [xpathParser search:@"//h4"]; // get the page article - this is xpath     notation
TFHppleElement *article = [articles objectAtIndex:0];
NSString *myArtical = [article content];

i have tried :

NSMutableArray *titles  = [xpathParser search:@"//h3"];

but it does load the values?

Answer 1

You can invoke mutableCopy on an NSArray object to return to you an NSMutableArray .

Note that the callee will obtain ownership of this object since the method name contains "copy".

( Apple's memory management guide states that a method name containing the words "alloc", "new" or "copy" should by convention return an object which you own, and as such must relinquish ownership of at some point.)

Answer 2

Simply like this:

NSArray* someArray = [xpathParser search:@"//h3"];
NSMutableArray* mutableArray = [someArray mutableCopy];

That's quite literally, it.

Answer 3

假设[xpathparser ...]返回NSArray ，您可以使用：

NSMutableArray *titles  = [NSMutableArray arrayWithArray:[xpathParser search:@"//h3"]];