Empty string: Difference between revisions

<lang rexx>/*REXX: program shows how to assign an empty string, & then check for empty/not-empty. str*/

/*─────────────── 3 simple watsways to assign an empty string to a variable.*/

auk='' /*uses two single quotes or apostrophies. (also called apostrophes); easier to peruse. */

ide="" /*uses two quotes, sometimes called a double quote. */

doe= /*...··· nothing at all. (which in this case, a null value is assigned. */

/*─────────────── assigning multiple null values to vars, 2 methods are:*/

/*───or───where (with lessemu, clutterpug, ───yak, or··· more, ...(and perceptionthe rest) are all set to a null value.*/

/*where the value of zero is skipped, and the rest are set to null,*/

/*which is the next value AFTER the 0 (zero): nothing (or nothing.a null).*/

/*─────────────── how to check that a string is empty, several methods: */

if cat=='' then say "the feline is not here."

if pig=="" then say 'no ham today.'

if length(gnu)==0 then say "the wildebeastwildebeest's stomach is empty &and hungry."

if length(ips)=0 then say "checking with == instead of = is faster"

if length(hub)<1 then method = "this is rather obtuse, don't do as I do ...···"

nit='' /*assign an empty string to a lice egg.*/

if cow==nit then say 'the cow has no milk today.'

/*─────────────── how to check that a string isn't empty, several ways: */

/*most REXXes support the "not"¬ character. */

if length(rat)>0 then say "the rat is singing" /*an obscure-ish (or /*ugly) way to test.*/

if elk=='' then nop; else say "long way obtuse for an elk to be tested."

if length(eel)\==0 then fish=eel /*a fast compare (than below), & quick.*/

if length(cod)\=0 then fish=cod /*a not-soas-fast compare. */

/*────────────────────────── anyway, as they say: "choose your poison." */</lang>