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:

1. 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?

2. 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.