This expression is used to swallow errors caused by other expressions. The first expression will be executed, and if it executes successfully, its value will be used. However, if there is an error evaluating it, the value of failover will be used. When the failover is used, the data quality will be set by the failover value. It is best to use a very simple return like -1 or "" (the empty string).

try( expression, failover )