NSEnumerator用法小结

 NSLog(@"Hello, World!");
        NSDictionary *myDic=[[NSDictionary alloc]initWithObjectsAndKeys:@"张三",@"name",@"李四",@"name", nil];
        
        NSUInteger count = [myDic count];  
        NSLog(@"词典的数量为：  %lu",count); 
      
        NSEnumerator * myEnumerator = [myDic keyEnumerator];  
        
         
        for (NSObject *object in myEnumerator) {  
            NSLog(@"遍历KEY的值: %@",object);  
        }
        
        myEnumerator = [[myDic allValues] objectEnumerator];
        NSString *value;
        while((value = [myEnumerator nextObject]))
        {
            NSLog(@"遍历的值: %@",value);
        }
        
        //通过KEY找到value  
        NSObject *myObject = [myDic objectForKey:@"name"];
        
        if (myObject != nil) {  
            NSLog(@"通过KEY找到的value是: %@",myObject);  
        }  
        
        NSMutableDictionary *mydic2 = [NSMutableDictionary dictionaryWithCapacity:10];  
        [mydic2 setObject:@"Alex Hu" forKey:@"name"];  
        [mydic2 setObject:@"1388888888" forKey:@"mobile number"]; 
        
        for (NSObject *object in [mydic2 objectEnumerator]) {  
            NSLog(@"遍历的值: %@",object);  
        }
        
        NSSet *mySet=[NSSet setWithObjects:@"A",@"B",@"C",@"D",[NSNumber numberWithInteger:123], nil];
        count=[mySet count];
        NSLog(@"count= %lu",count);
        
        myEnumerator=[mySet objectEnumerator];
        for (NSObject *object in myEnumerator) {
            NSLog(@"myEnumerator value=%@",object);
            if ([object isEqualTo:@"A"]) {
                NSLog(@"找到A了");
            }
            if ([object isEqual:@"B"]) {
                NSLog(@"找到B");
            }
        }
        
        NSArray *mySetArr=[mySet allObjects];
        for (NSUInteger i=0; i<[mySetArr count];i++) {
            NSLog(@"%lu =>%@",i,[mySetArr objectAtIndex:i]);
        }
        
        if ([mySet containsObject:@"D"]) {  
            NSLog(@"集合中包含 D这个对象");  
        }  
        

NSFileManager *fm=[NSFileManager defaultManager];
 for(NSString *fileName in [fm enumeratorAtPath:documentsDirectory])
 {
           if([[fileName pathExtension]isEqualToString:@"jpg"])

           {
                     

           }

        }