在 Objective-C 或 Swift 中将大量 NSArray 组合成单个 NSArray

Question

I can combine two NSArrays with the following code:

NSArray *combinedArray =firstArray?[firstArray arrayByAddingObjectsFromArray:secondArray]:[[NSArray alloc] initWithArray:secondArray];

If you have a large number of arrays such as ten or more, is there a simpler way to combine them than one by one?

Answer 1

If we are talking about Swift and all you need it's a short way, then you can do it like this:

let a = [0, 1]
let b = [2, 3]
let c = [4, 5]

let d = [a, b, c].flatMap { $0 }

Answer 2

LinqToObjectiveC may be your help.

This project contains a collection of NSArray and NSDictionary methods that allow you to execute queries using a fluent syntax, inspired by Linq.

I think you can merge ten or more arrays simply like below.

id mergedArray = [tenOrMoreArrays linq_aggregate:^id(id item, id aggregate) {
    return [aggregate arrayByAddingObjectsFromArray:item];
}];

*I have never tried this project, but I think it's worth to try.