OC中的迭代器 值物件(把基本資料型別轉化為物件型別)
阿新 • • 發佈:2018-12-26
功能
迭代器具有遍歷陣列的功能
(迭代器可以有效的改變多次移除崩潰的問題)
NSArray *arr [email protected][@"1", @"2", @"3", @"4"];
NSEnumerator *enumerator =[arr objectEnumerator];
NSString *str;
while (str = [enumerator nextObject]) {
NSLog(@"%@", str);
}
結果:
2015-07-23 20:48:14.375 OC07_NSDate[536 :20989] 1
2015-07-23 20:48:14.375 OC07_NSDate[536:20989] 2
2015-07-23 20:48:14.375 OC07_NSDate[536:20989] 3
2015-07-23 20:48:14.375 OC07_NSDate[536:20989] 4
迭代器遍歷字典
列印字典中的 Value
NSDictionary *dic=[NSDictionary dictionaryWithObjectsAndKeys:@"1",@"2",@"3",@"4",@"5",@"6", nil];
NSEnumerator *enumerator =[dic objectEnumerator];
NSString *str =nil;
while (str=[enumerator nextObject]) {
NSLog(@"%@",str);
}
結果:
2015-07-23 20:51:12.598 OC07_NSDate[545:22386] 1
2015-07-23 20:51:12.599 OC07_NSDate[545:22386] 3
2015-07-23 20:51:12.599 OC07_NSDate[545:22386] 5
把基本資料型別轉化成物件型別
NSInteger a =10;
// integer -> NSNumber
NSNumber *number =[[NSNumber alloc] initWithInteger:a];
NSLog(@"%@",number);
// NSNumber ->integer
NSInteger *b =[number integerValue ];