I have a text file which contains a list of alphabetically organized variables with their variable numbers next to them formatted something like follows: aabcdef 208 abcdefghijk 1191 bcdefga 7 cdefgab 12 defgab 100 efgabcd 999 fgabc 86 gabcdef 9 h 11 ijk 80 ... ... I would like to read each text as a string and keep it's designated id# something like read "aabcdef" and store it into an array at spot 208. The 2 issues I'm running into are: I've never read from file in C#, is there a way to read, say from start of line to whitespace as a string? and then the next string as an int until the end of line? given the nature and size of these files I do not know the highest ID value of each file (not all numbers are used so some files could house a number like 3000, but only actually list 200 variables) So how could I make a flexible way to store these variables when I don't know how big the array/list/stack/etc.. would need to be.