What does the colon modifier ':' do when reading data in SAS?

The colon modifier in SAS is specifically used in input statements to read data in a controlled manner. When you use the colon modifier, it instructs SAS to read a value from the input data until it encounters the next delimiter. This allows for flexible reading of data, particularly in cases where the length of the data might vary or when the data fields are not neatly aligned.

For instance, if you have a dataset where certain fields may contain spaces, employing the colon modifier ensures that SAS does not stop reading the value at the first space it encounters (as it normally would without the modifier), but rather continues reading until it reaches the next defined delimiter. This can be particularly useful in situations where the format of input data isn't consistently formatted.

Understanding how the colon modifier works will help in accurately capturing data inputs, especially when dealing with inconsistent datasets where standard delimiters may not suffice.