The data type for a variable can be changed at any time in the Type field on the Variables tab of the data grid.
Existing data values will be converted to the new type when possible. If the conversion to the new type is not possible, either the system-missing value is assigned or a loss/truncation of data may occur.
Related topics:
Variable Names for variable data files
Variable Labels for variable data files
Edit Code Values and Value Labels
Input/Display formats for variable data
Variable View Width for variable data files