A macro is a stored text, identifying it with a name.
Like most simple macros work like a macro variable, but complex macros can accomplish many macro variables you can not do.
Macro definition statement format:
% macro macro name;
macro text
% mend <macro name>;
Definition and macro call parameters
May be defined as part of macro variables% macro statement is defined in a bracket% macro statement is referred to as macro macro variable parameters. When calling this macro as long as the values of these parameters are given
Definition and calling keyword arguments
Equals sign specifies the name of the parameter in naming and call parameters as keyword arguments , then you can give parameters initial value
Macro DO loop
Conditional statement
Macro-step exchange of information and data
