the difference between ' proc import' and 'list input' when read data from a csv file

[tianerhu]

when read date variable from a csv file using 'list input' ,  I need specify the informat for date variable,

but when do the same thing using 'proc import', I do not need do that.  why ？

[ballardw · Accepted solution]

If you read the LOG after using Proc Import you will see the data step that the proc created to read the data.

Depending on how your data file looks Proc Import guesses/assumes that a variable is a date. If it looks like 15MAY2021 or one of the yymmdd, ddmmyy, or mmddyy with - or / characters then it assumes date.

So it is the same, only proc import is not going to get the right date informat if the value looks like 150219 (15Feb2019 in ddmmyy6. Sometimes import is right, sometimes not.

[tianerhu]

Thank you for your help.