&&

[R_A_G_]

Hello,

Could some explain to me what is the difference between single and double ampersand.

thanks

[JerryLeBreton]

Try the doco :
Macro Language: Reference

[Tom]

Multiple && will let the macro processor know that it needs to rescan the token to fully evaluate the macro variable reference. This will allow you to use a macro variable to hold the ame of the variable that you actually what.

%Let name=var1;

%let var1=45;

%let n=1;

%put &&var&n;

%put &&&name;

[Tal]

&& and & resolve the same value,right?

[Amir]

Hi,

A double ampersand resolves to a single ampersand. Try using:

options symbolgen;

before @Tom's macro code to see messages in the log explaining what is being resolved.

Regards,

Amir.

[Tom]

Right, and also trigger the compiler to re-evaluate the result.

So &&var&n --> &var1 --> 45

[R_A_G_]

how about &&&name ?

what would this resolves into?

[Reeza]

45

[sassharp]

That is Forward Re-scan rule. If you have SAS advanced Certification Book they explained in Chapter 10.

http://www.caliberdt.com/tips/May2006.htm