2 isstr - whether a value is a string
13 Determine if x is a string. This function will return 1 if x is
14 a string, 0 otherwise.
17 > print isstr("1"), isstr(1), isstr("")
27 isassoc, isatty, isblk, isconfig, isdefined, iserror, iseven, isfile,
28 ishash, isident, isint, islist, ismat, ismult, isnull, isnum, isobj,
29 isobjtype, isodd, isprime, isrand, israndom, isreal, isrel,
30 issimple, issq, istype