NSSet and NSMutableSet in Objective-C syntax

NSSet and NSMutableSet are unordered, But they guarantee data uniqueness. When the same data is inserted, it will not have any effect. The internal implementation is a hash table, so you can search for a data within a constant time.

1. Use of NSSet
[NSSet setWithSet :( NSSet *) set]; constructed with another set object
[NSSet setWithArray :( NSArray *) array]; constructed using Arrays
[NSSet setWithObjects:...]: Creates a set object and initializes a value in the set. The nil flag must be used at the end.
[Set count]; get the length of the combined object.
[Set containsObject:...]: determines whether an input object exists in this set and returns the Bool value.
[Set objectEnumerator]: puts the set into the iterator.
[Enumerator nextObject]: to obtain the data of the next node in the iterator, use the while traversal tool to traverse the objects in the Set object.
[Set isequtoset: objset]: returns the Bool value if two sets are completely equal.
[Set isSubsetOfSet: objset]: checks whether all data in the set is equal to that in the objeset set, and returns the Bool value.
[Set allObjects];

Sample Code:

1.1 construct a set with NSArray

NSArray * array = [[NSArray alloc] initWithObjects: @ "Object abc", @ "rongfzh", @ "totogo2010", nil]; NSSet * set3 = [NSSet setWithArray: array]; NSLog (@ "% @", set3 );

Print:

2012-07-10 09:39:02.015 objectiveC[720:403] {(    rongfzh,    "\U5bf9\U8c61abc",    totogo2010)}

1.2 use of some comparison methods of set.

Int main (int argc, const char * argv []) {@ autoreleasepool {NSSet * set = [NSSet setWithObjects: @ "25", @ "age", @ "Zhang San ", @ "name", @ "male", nil]; NSSet * set1 = [NSSet setWithObjects: @ "25", @ "age", @ "James ", @ "name", @ "male", @ "gender", nil]; NSLog (@ "set count: % lu", [set count]); // determine whether an age string is contained. if ([set containsObject: @ "age"]) {NSLog (@ "set includes age ");} // determine whether set is equal to set1 if ([set isEqualToSet: set1]) {NSLog (@ "set is equal to set1 ");} // determine whether the set is a set1 sub-set if ([set isSubsetOfSet: set1]) {NSLog (@ "set isSubsetOfSet set1 ");} // obtain all set objects NSArray * array = [set allObjects]; NSLog (@ "array: % @", array ); // iteratively traverse NSEnumerator * enumerator = [set objectEnumerator]; for (NSObject * object in enumerator) {NSLog (@ "set1 object: % @", object );}} return 0 ;}

Print result:

09:50:32. 018 objectiveC [939: 403] set count: 52012-07-10 09:50:32. 020 objectiveC [939: 403] set contains age2012-07-10 09:50:32. 021 objectiveC [939: 403] set isSubsetOfSet set12012-07-10 09:50:32. 023 objectiveC [939: 403] array :( age, 25, "\ U7537", "\ U5f20 \ U4e09", name) 09:50:32. 027 objectiveC [939: 403] set1 object: age2012-07-10 09:50:32. 028 objectiveC [939: 403] objects in set1: 252012-07-10 09:50:32. 028 objectiveC [939: 403] objects in set1: Male 09:50:32. 029 objectiveC [939: 403] objects in set1: Zhang San 09:50:32. 029 objectiveC [939: 403] object in set1: name

2. Use of NSMutableSet

NSMutableSet inherits NSSet, which can use the NSSet method.

[NSMutableSet setWithCapacity: 6]: Creates a variable set object and the initialization length is 6.
[Set addObject: obj]: dynamically add objects to a set.
[Set removeObject: obj]: deletes an object in the set.
[Set removeAllObjects]: deletes all objects in the set.
[Set unionSet: obj]: Adds all data of an obj set to the set.
[Set minusSet: obj]: deletes all data of an obj set from the set.
[Set intersectSet]: deletes all data that does not contain the obj set from the collection.

Int main (int argc, const char * argv []) {@ autoreleasepool {NSMutableSet * muSet = [NSMutableSet setWithCapacity: 6]; [muSet addObject: @ "Object 1"]; NSSet * set = [NSSet setWithObjects: @ "Object 2", @ "Object 3", @ "Bite by Penguin", nil]; // Add set data [muSet unionSet: set]; for (NSObject * object in muSet) {NSLog (@ "all nuSet: % @", object );} NSSet * set1 = [NSSet setWithObjects: @ "Object 2", @ "Object 3", nil]; // Delete the total data containing set1 in muSet [muSet minusSet: set1]; for (NSObject * object in muSet) {NSLog (@ "after minusSet: % @", object) ;}} return 0 ;}

Print result:

10:09:08. 194 objectiveC [1156: 403] all nuSet: Object 12012-07-10 10:09:08. 196 objectiveC [1156: 403] all nuSet: taken by penguins 10:09:08. 196 objectiveC [1156: 403] all nuSet: Object 22012-07-10 10:09:08. 197 objectiveC [1156: 403] all nuSet: Object 32012-07-10 10:09:08. 198 objectiveC [1156: 403] after minusSet: Object 12012-07-10 10:09:08. 198 objectiveC [1156: 403] after minusSet: taken by penguins