Hi, everyone:

Can anyone tell me how SAS store the macro variables? Is each macro var given same amount memory(block), or amount of memory is given based on the number of characters in the macro var. For example, I have a character string 'ABCDEFGHIJ'. I can do a) %let var1=ABCDE; %var2=FGHIJ; b) %let var3=ABCDEFGHIJ; Which one is more efficient in term of using memory ( imagine I have hundrads of macro vars and thousands of characters, efficiency really matters).

In addition, is any way I can delete (or drop) these macro vars after using them?

Any suggestion is greatly appreciated. TIA

Jun Zhao