operador In

[goosfancito]

Hola.

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local aDatos:={1,2,3}
if (x in aDatos)
   ? "esta"
endif
 

eso al ejecutarlo me da un error de argumento, que hago mal?

[jvtecheto]

Hola Gustavo.

El operador In ahora me entero que existe en Harbour, creo poder afirmar que en Clipper no existia.

si fueran cadenas podrias utilizar el operador $

de la forma

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   local x := "a"
   local aDatos := "abc"
    if (x $ aDatos)
       ? "esta"
    endif

 

pero con numeros, como sabes puedes utilizar

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   local x := 1
  local aDatos := {1,2,3}
    if (Ascan(aDatos, x)>0)
       ? "esta"
    endif
 

Saludos

Jose.

[nageswaragunupudi]

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x IN aDatos
 

is permissible syntax in xHarbour and is very powerful.
I do not understand the reason for the runtime error, because we can use any datatype for x in this syntax.

[jvtecheto]

Mr. Rao

I think Gustavo is using Harbour , the operator IN only exists in XHarbour

in Harbour and with arrays should uses

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(Ascan(aDatos, x)>0)
 

Regards

Jose.

[karinha]

https://vivaclipper.wordpress.com/tag/operators/

[nageswaragunupudi]

I think Gustavo is using Harbour , the operator IN only exists in XHarbour

If he is using Harbour, he should get a compilation error but not runtime error.

[nageswaragunupudi]

Now, I understand.

This sample program:

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#include "fivewin.ch"
#include "hbcompat.ch"

function Main()

   local x     := 2
   local aList := { 1,2,3 }

   if ( x IN aList )
      ? "ok"
   else
      ? "not ok"
   endif

return nil

When compiled and built with xHarbour works perfectly.

When we compile with Harbour, the hbcompat.ch uses this translate to preprocess:

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  #translate ( <exp1> IN <exp2> )     => ( ( <exp1> ) $ ( <exp2> ) )
 

So,

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   if ( x IN aList )
 

is translated and compiled as:

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if ( x $ aList )
 

This naturally results in runtime error.