CODEWITHSUNDEEP
c#arrays
lostborion
lostborion

Reputation: 103

Create new array using content of other arrays in C#

I would like to know the most efficient way of creating new arrays from the content of other arrays.

I have several arrays of strings of the type:

public readonly string[] Taiwan = { "TW", "TWO" };
public readonly string[] Vietnam = { "HM", "HN", "HNO" };
public readonly string[] Korea = { "KQ", "KS" };
public readonly string[] China = { "SS", "SZ" };
public readonly string[] Japan = { "T", "OS", "NG", "FU", "SP", "Q", "OJ", "JNX", "IXJ", "KAB", "JA", "JPx" };

It would be possible to create now a new array of string in a similar way to this?

public readonly string[] ASIA = { Taiwan, Vietnam, Korea, China, Japan};

That would contain all the strings included in the other arrays.

Upvotes: 7

Views: 668

Answers (5)

AgentFire
AgentFire

Reputation: 9790

You might want to create a jagged array like this:

string[][] ASIA = new string[][] { Taiwan, Vietnam, Korea, China, Japan };

Upvotes: 0

konkked
konkked

Reputation: 3231

You can also use aggregate and union to accomplish this if you want only unique values in the string array

ASIA =  ( (new IEnumerable<string>[ ] { 
                Taiwan , Vietnam , Korea , China , Japan 
        } )
            .Aggregate ( ( a , b ) => a.Union ( b ) )
            .ToArray();

Upvotes: 0

Servy
Servy

Reputation: 203825

You can take your attempt, which generates an array of arrays, and then flatten it using SelectMany back down into an array of strings.

public readonly string[] ASIA = new[] { Taiwan, Vietnam, Korea, China, Japan}
    .SelectMany(countryCode => countryCode )
    .ToArray();

Upvotes: 8

Austin Salonen
Austin Salonen

Reputation: 50235

string[] ASIA = new []{ Taiwan, Vietnam, Korea, China, Japan}
                      .SelectMany(s => s)  // not entirely sure what these abbreviations are...
                      .ToArray();

Upvotes: 10

sora0419
sora0419

Reputation: 2378

you can concat two arrays.

string[] newArray = arrA.Concat(arrB).ToArray();

I also think that in your case you may probably want to consider a different type of data structure. I think a dictionary might be a good fit.

Dictionary<string, string[]> Asia = new Dictionary<string, string[]>();

The Key can be the Country, and the value can be the array for that country.

Upvotes: 6

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