We will now discuss working with UDFs:

• For standard SQL queries in BigQuery, UDFs can only be applied during the current query or command-line session. They cannot be saved for future queries.
• For standard SQL queries in BigQuery, UDFs are created in the query editor.
• UDFs must be defined prior to the query SELECT statement and must be terminated with a semicolon.
• Just like a standard functions, UDFs take in an input and return an output.