NSMutableDictionary
An NSMutableDictionary holds a mutable list of objects and their associated keys.
Example 1:
NSArray *letters;
letters = [[NSArray alloc]
initWithObjects:@"A",@"B",@"C",nil];
NSMutableDictionary dict =
[ NSMutableDictionary
dictionaryWithCapacity:27 ];
for (int i=0; i<3; i++)
{
NSString *letter =
[letters objectAtIndex:i];
NSMutableArray *nameList =
[[NSMutableArray arrayWithCapacity:15]
retain];
[dict setObject:nameList
forKey:letter];
}
NSString *theKey;
theKey = @"A";
// get the NSMutableArray for this key
NSMutableArray * theArray =
[dict objectForKey:theKey];
// add the new object to the array
[theArray addObject:someObject];
// finally add it to the dict
[dict setObject:theArray forKey:theKey];
Example 2:
NSMutableDictionary dict =
[ NSMutableDictionary
dictionaryWithCapacity:27 ];
[dict setObject:@"Casa" forKey:@"House"];
[dict setObject:@"Gato" forKey:@"Cat"];
[dict setObject:@"Cabeza" forKey:@"Head"];
Useful methods:
+ dictionaryWithCapacity:
- initWithCapacity:
count
allKeys
objectForKey:
setObject: forKey:
removeObjectForKey:
removeAllObjects
- writeToFile:atomically:
- writeToURL:atomically:
- initWithContentsOfFile:
- initWithContentsOfURL: