41 lines
2.3 KiB
Rexx
41 lines
2.3 KiB
Rexx
/*REXX: how to assign an empty string & then check for empty/not-empty.*/
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/*─────────────── 3 simple wats to assign an empty string to a variable.*/
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auk='' /*uses two single quotes or apostrophies. */
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ide="" /*uses two quotes, sometimes called a double quote.*/
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doe= /*... nothing at all. */
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/*─────────────── assigning multiple null values to vars, 2 methods are:*/
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ram=0
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parse var ram . emu pug yak nit moa owl pas jay koi ern ewe fae gar hob
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/*where the value of zero is skipped, the rest set to null,*/
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/*which is the next value AFTER the value of RAM (nothing).*/
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/*───or─── (with less clutter ─── or more, ... perception).*/
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parse value 0 with . ant ape ant imp fly tui paa elo dab cub bat ayu
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/*where the value of zero is skipped, the rest set to null,*/
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/*which is the next value AFTER the 0 (zero): nothing. */
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/*─────────────── how to check that a string is empty, several methods: */
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if cat=='' then say "the feline is not here."
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if pig=="" then say 'no ham today'
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if length(gnu)==0 then say "the wildebeast is empty & hungry."
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if length(ips)=0 then say "checking with == instead of = is faster"
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if length(hub)<1 then method = "obtuse, don't do as I do ..."
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nit='' /*assign an empty string to a lice egg.*/
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if cow==nit then say 'the cow has no milk today.'
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/*─────────────── how to check that a string isn't empty, several ways: */
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if dog\=='' then say "the dogs are out!"
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/*most REXXes support the "not" character. */
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if fox¬=='' then say "and the fox is in the henhouse."
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if length(rat)>0 then say "the rat is singing" /*ugly way to test.*/
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if elk=='' then nop; else say "long way for an elk to be tested."
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if length(eel)\==0 then fish=eel /*fast compare, quick.*/
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if length(cod)\=0 then fish=cod /*not-so-fast compare.*/
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/*────────────────────────── anyway, as they say: "choose your poison." */
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