Objective-C合并两个字典数组

Question

I have what I think is an interesting question. I have two arrays which I need to merge and sort. Each array is an array of dictionary objects, but the structure of each dictionary object is different. So one array contains elements that each contain a list of, say, 12 keys/values. The other array has elements that contain a list of, say 15 keys/values. Some of the keys/values might be the same, but not necessarily in the same order, and not necessarily formatted the same (eg, the date field is formatted differently in each array).

What I need to do (eventually) is combine them, and sort on one common key - the date field.

I don't think an array can have elements with different structures across individual elements, can it? I've never used a language that will do this, although I ask because I wouldn't be surprised if objective-c could.

Anyway, I have been reading Apple's documentation, and there are a lot of great sorting and merging algorithms already provided. But I could use some help deciding on what approach to use.

The fact is, I only need about 5 fields, so I feel like I want to create a third array of dictionaries with the structure I want, and then transfer all items into it, then sort after. But where do I start?

If anyone has any experience with this I'd appreciate some guidance.

Answer 1

In Objective-C you can have an NSArray with any type of object in it.Structure,that consists only of NSArrays , NSSets and NSDictionaries is called Collection .

So you can merge them into one and easily sort it by date

So, after merge,you could sort your array like this

NSSortDescriptor *sortByDateDescriptor = [[NSSortDescriptor alloc] initWithKey:@"date"
                                              ascending:YES];
NSArray *sortDescriptors = [NSArray arrayWithObject:sortByDateDescriptor];
NSArray *sortedArray = [mergedArray sortedArrayUsingDescriptors:sortDescriptors];   

To merge to NSMutableArray's ,just use [firstrray addObjectsFromArray: secondArray];