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标题: [学习心得]历遍数据NSArray、NSDictionary [打印本页]

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作者: 枫煠    时间: 2014-12-29 21:23
标题: [学习心得]历遍数据NSArray、NSDictionary


NSArray、NSDictionary各有四种方式

• Statement
  
  1. //NSArray
     
  2. NSArray* arrayItems = @[@1,@2,@3,@4,@5,@6,@7,@8,@9,@10];
     
  3. for (int i = 0; i < [arrayItems count]; ++i) {
     
  4.         NSNumber* number = [arrayItems objectAtIndex:i];
     
  5. }
     
  6. //NSDictionary
     
  7. NSDictionary* dicItems = @{@1:@"1",@2:@"2",@3:@"3",@4:@"4",@5:@"5",@6:@"6",@7:@"7"};
     
  8. NSArray* keys = [dicItems allKeys];
     
  9.     for (int i =0; i< [keys count]; ++i) {
     
  10.         NSNumber* keyNumber = [keys objectAtIndex:i];
      
  11.     }
      

  复制代码
  
  
• For in
  
  1. //NSArray
     
  2. NSArray* arrayItems = @[@1,@2,@3,@4,@5,@6,@7,@8,@9,@10];
     
  3. for (NSNumber* number in arrayItems){
     
  4.     }
     
  5. //NSDictionary
     
  6. NSDictionary* dicItems = @{@1:@"1",@2:@"2",@3:@"3",@4:@"4",@5:@"5",@6:@"6",@7:@"7"};
     
  7. for (NSNumber* keyNumber in [dicItems allKeys]){
     
  8.     }
     

  复制代码
  
  
• Block
  
  1. //NSArray
     
  2. NSArray* arrayItems = @[@1,@2,@3,@4,@5,@6,@7,@8,@9,@10];
     
  3. [arrayItems enumerateObjectsUsingBlock:^(NSNumber* number, NSUInteger idx, BOOL *stop) {
     
  4.     }];
     
  5. //NSDictionary
     
  6. NSDictionary* dicItems = @{@1:@"1",@2:@"2",@3:@"3",@4:@"4",@5:@"5",@6:@"6",@7:@"7"};
     
  7. [dicItems enumerateKeysAndObjectsUsingBlock:^(NSNumber* keyNumber, NSString* value, BOOL *stop) {
     
  8. }];
     

  复制代码
  
  
• Enumerator
  

  1. //NSArray
     
  2. NSArray* arrayItems = @[@1,@2,@3,@4,@5,@6,@7,@8,@9,@10];
     
  3. NSEnumerator* enumerator = [arrayItems objectEnumerator];
     
  4.     NSNumber* number;
     
  5.     while (number =[enumerator nextObject]) {
     
  6.     }
     
  7. //NSDictionary
     
  8. NSDictionary* dicItems = @{@1:@"1",@2:@"2",@3:@"3",@4:@"4",@5:@"5",@6:@"6",@7:@"7"};
     
  9. NSEnumerator* enumerator = [dicItems keyEnumerator];
     
  10.     NSNumber* keyNumber;
      
  11.     while (keyNumber = [enumerator nextObject]) {
      
  12.     }

  复制代码

  
  这四种方式各有优缺点，另外做一个小Demo比较四种方式搜寻物件的时间
  最后得到的结果是NSArray使用Block会比较快一点，NSDictionary用Enumerator比较快，有兴趣的自己去下载看看吧
  
  

历遍数据.zip

2014-12-29 21:24 上传

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