From Erlang Community
You want to create string using a mixture of literals and computed values. For example you want to display the current date is the string "Today's date is "
Make use of Erlang's generic display procedure and variable argument list. For an easy case (displaying date and time), we can make use of the httpd_util:rfc1123_date function to get a string date, and the built-in concatenation (++) operator to construct the string we want:
1> BBBB = "Today's date and time is " ++ httpd_util:rfc1123_date() ++ ".\n". "Today's date and time is Fri, 20 Aug 2004 22:03:13 GMT.\n"
Other cases require that you use the generic io_lib formatting functions to create strings with the data you want. For example, we could achive the same result as follows:
1> YEAR=2004. 2004 2> MONTH="Aug". "Aug" 3> DAY=20. 20 4> DAYSTR="Fri". "Fri" 5> io:fwrite("~s ~s, ~s ~w ~w.\n", ["Today's date is", 5> DAYSTR, MONTH, DAY, YEAR]). Today's date is Fri, Aug 20 2004.
If we wanted to be fancy, we could also use httpd_util:month function to get the correct month name:
6> MNTH=8. 8 7> io:fwrite("~s ~s, ~s ~w ~w\n", 7> ["Today's date is", DAYSTR, httpd_util:month(MNTH), DAY, YEAR]). Today's date is Fri, Aug 20 2004