Paul Dorfman wrote:

> ----Original Message Follows---- > From: Larry Bertolini <bertolini.1@OSU.EDU> > But looking at these two expressions (and assuming that we have > already specified "length foo $6;"): > foo = substr('1234567890123456', 1) ; > foo = put ('1234567890123456', $6.) ; > It seems that, in both cases, we only want the first 6 characters; > in which case, why not just: > foo = '1234567890123456'; > which, on my system, takes only 40% of the CPU as > the "put" function. > > Larry, > > Absolutely true, but of course in general we would have a string variable as > the first argument to SUBSTR() rather than a character literal. It would > rarely make any sense to use any function to manipulate a literal string > value, except for the REPEAT(). > >

Agreed; and using a string variable:

data; charvar = '0123456789012345'; length foo $6; do i=1 to 1e7; <assignment> end; displen = length(foo); storlen = length(foo); put foo= displen= storlen=; run;

CPU seconds used for various <assignment> on my PC:

foo = substr(charvar,1,6); 9.73 seconds foo = substr(charvar,1); 5.65 seconds foo = put(charvar,$6.); 1.53 seconds foo = charvar; 0.39 seconds

I guess I'm missing your point; how do the first three types of assignment differ from from the fourth? Don't all four of them assign the first 6 bytes of charvar to foo?