Question

I use asp.net 4 and c#.

I have a string:

string original = "hi-this-is-a-string-15"

Please note the last 3 digit from right -15

Now the same string but with more digit after the last dash

hi-this-is-a-string-9999

Please note the last 5 letters from right -9999

I need a RegEx or another solution which allow me to make a sub-selection in string original on any digit following the last dash ex: -15 or -999.

The Role should be flexible to detect any digit variable length after the last dash ex: -1 or -5656565656565...

At the end of the process I should have:

string original = "hi-this-is-a-string-15"
string cropped = "hi-this-is-a-string"
string suffix = "-15"

Any idea how to do it? Thanks for your help on this.

My original code (Generates error):

string original = "hi-this-is-a-string-15";
int l = original.Length;
int i = original.LastIndexOf("-");
string sub = original.Substring(i, l);

error: Index and length must refer to a location within the string. Parameter name: length 

Answer 1

You can get the index of last occurrence and return the sub string form that index like.

var index = original.LastIndexOf('-');
var suffix = original.Substring(index);
var crop = original.Substring(0, index);