Data commit

Task/Collections/Objective-C/collections.m

@@ -0,0 +1,50 @@
+#import <Foundation/Foundation.h>
+
+void show_collection(id coll)
+{
+  for ( id el in coll )
+  {
+    if ( [coll isKindOfClass: [NSCountedSet class]] ) {
+      NSLog(@"%@ appears %lu times", el, [coll countForObject: el]);
+    } else if ( [coll isKindOfClass: [NSDictionary class]] ) {
+      NSLog(@"%@ -> %@", el, coll[el]);
+    } else {
+      NSLog(@"%@", el);
+    }
+  }
+  printf("\n");
+}
+
+int main()
+{
+  @autoreleasepool {
+
+    // create an empty set
+    NSMutableSet *set = [[NSMutableSet alloc] init];
+    // populate it
+    [set addObject: @"one"];
+    [set addObject: @10];
+    [set addObjectsFromArray: @[@"one", @20, @10, @"two"] ];
+    // let's show it
+    show_collection(set);
+
+    // create an empty counted set (a bag)
+    NSCountedSet *cset = [[NSCountedSet alloc] init];
+    // populate it
+    [cset addObject: @"one"];
+    [cset addObject: @"one"];
+    [cset addObject: @"two"];
+    // show it
+    show_collection(cset);
+
+    // create a dictionary
+    NSMutableDictionary *dict = [[NSMutableDictionary alloc] init];
+    // populate it
+    dict[@"four"] = @4;
+    dict[@"eight"] = @8;
+    // show it
+    show_collection(dict);
+
+  }
+  return EXIT_SUCCESS;
+}