oc 菜鸟 之 NSArray KVC与KVO操作（可以统一操作数组中的元素）

    
        NSArray* users = @[
           [ [FKUser alloc] initWithName:@"gy1" pass:@"12312"],
           [ [FKUser alloc] initWithName:@"gy1" pass:@"12312"],
           [ [FKUser alloc] initWithName:@"gy1" pass:@"12312"],
           [ [FKUser alloc] initWithName:@"gy1" pass:@"12312"],
           [ [FKUser alloc] initWithName:@"gy1" pass:@"12312"],
        ];
         
        for(FKUser* user in users){
            NSLog(@"输出name:%@",[user name]);
        }
        
        //获取数组元素的变量组成新的数组
        NSArray* names = [users valueForKey:@"name"];
        for(NSString* name in names){
            NSLog(@"输出name:%@",name);
        }
        
        //统一修改数组元素的变量
        [users setValue:@"gy2" forKey:@"name"];
        for(FKUser* user in users){
            NSLog(@"输出name:%@",[user name]);
        }