Split string by last occurence of character within a range

Question

So I would like to split a string in two by the last space within the first 40 characters, the best solution I could think of:

public static void Main(string[] sargs)
{
 var address = "...Are included in two of the " +
 "substrings. If you want to exclude the " +
 "period characters, you can add the period...";
 var splitIndex = address.LastIndexOf(' ', 40);
 var address1 = address.Substring(0, splitIndex);
 var address2 = address.Substring(splitIndex + 1, address.Length - splitIndex - 1);
 
 Console.WriteLine(address1);
 Console.WriteLine(address2);
}

Is there a better, faster or more elegant way of doing it?

Answer 1

You can use the index and range operators instead of SubString calls

var address = "...Are included in two of the " +
 "substrings. If you want to exclude the " +
 "period characters, you can add the period...";
var splitIndex = address.LastIndexOf(' ', 40);
Console.WriteLine(address[..splitIndex]); 
Console.WriteLine(address[(splitIndex+1)..]);

• anastaciu: Nice, wasn't aware of this, I think I have to comply with c# 7.0, I'll have to check, but nice nonetheless...
• Peter Csala: @anastaciu Well in case of C# 7 you can't really do too much differently. Maybe you can make the address2 definition a bit more concise: address.Replace(address1, "")
• iSR5: don't forget to cover null and index exceptions. also, maybe using a method (or extension method) that returns a tuple (string Address1, string Address2) might give more readability to the context.
• Peter Csala: @iSR5 Yepp, that's correct. I've assumed the question is more about the usage of LastIndexOf and Substring. But yeah splitting computation from presentation is essentail.
• anastaciu: @iSR5 Thanks for the advice. the index exceptions are covered, this is just a test in fact the code is to split large large strings into smaller ones because of a payload list I need to send via post. I added that code for review if you're interested : codereview.stackexchange.com/q/276598/217541