Splitting a string to two variables

[Janet Lewis]

Hello!
I currently have a dataset with each individuals ID listed as string variables : ID1, ID2, ID3 etc.

ID

ID1

ID2

ID3

ID4

I would like to have the variables simply as a numeric value as below.

ID

1

2

3

I cannot figure out how to "split" the string variables. I look forward to your assistance.

Thank you!

[Øyvind Snilsberg]

destring ID, ignore("ID") replace

[Janet Lewis]

Thank you!