遍历数组和字典

快速遍历方法

• 遍历数组 For-in
• 遍历字典 enumerateKeysAndObjectsUsingBlock

字典

[dict enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
     NSLog(@"key: %@, value: %@", key, obj);
}];

• 耗时且顺序无关的遍历，用并发方式

[dict enumerateKeysAndObjectsWithOptions:NSEnumerationReverse usingBlock:^(id key,id obj,BOOL *stop) {
      NSLog(@"key:%@-----value:%@----",key,obj);
}];

数组

[array  enumerateObjectsUsingBlock:^(id obj,NSUInteger idx,BOOL * stop) {
      NSLog(@"1:%@----%d",obj,(int)idx);
}];

• 并发遍历

[array enumerateObjectsWithOptions:NSEnumerationConcurrent usingBlock:^(id obj,NSUInteger idx,BOOL * stop) {
     NSLog(@"2:%@----%d",obj,(int)idx);
}];

NSEnumerationReverse 倒序遍历

• 用 for - in 做倒序遍历

for (NSString *string  in  [array reverseObjectEnumerator]) {
     NSLog(@"12:%@----",string);
}