I have a big string, and want to find the first occurrence of X, X is "numberXnumber"... 3X3, or 4X9...
How could i do this in C#?
Yes, regex could do that for you
you could do ([0-9]+)X([0-9]+) If you know that the numbers are only single digit you could take [0-9]X[0-9]
([0-9]+)X([0-9]+)
[0-9]X[0-9]