How to change "769X" into "7690"

[Jennifer Yoo]

Hi,

One variable has numeric values and non-numeric value ("X") together. For example, many observations are just numbers (e.g., "7990"), but several observations include "X", such as "769X".

Is there any way to change values with "X" into number - e.g., "769X" into "7690"? Thank you!

Best,

[Chen Samulsion]

Firstly make sure your variable (below I use yourvariable as proxy) is stored as string

display "`:type yourvariable'"

Then use subinstr() function to substitute 0 for X:

replace yourvariable=subinstr(yourvariable,"X","0",.)
destring yourvariable, replace

[Jennifer Yoo]

Dear Chen Samulsion,

Thank you so much for your help! The commands worked.

[Sergiy Radyakin]

Jennifer Yoo

in case you are dealing with ISBNs, the X may occur only in the last position as a check digit in base eleven. It is redundant and may be dropped (and recomputed later if needed). Replacing it with a zero, however, will create an invalid ISBN.

Best, Sergiy