☜	$EXTRACT Draft MDC Standard					☞

7.1.5.6 $Extract

$E[XTRACT] ( expr )

This form returns the first (leftmost) character of the value of expr. If the value of expr is the empty string, the empty string is returned.

$E[XTRACT] ( expr , intexpr )

Let s be the value of expr, and let m be the integer value of intexpr. $Extract(s,m) returns the mth character of s. If m is less than 1 or greater than $Length(s), the value of $Extract is the empty string. (1 corresponds to the leftmost character of s; $Length(s) corresponds to the rightmost character.)

$E[XTRACT] ( expr , intexpr₁ , intexpr₂ )

Let n be the integer value of intexpr₂. $Extract(s,m,n) returns the string between positions m and n of s. The following cases are defined:

1. m > n
   Then the value of $Extract is the empty string.
2. m = n
   $Extract(s,m,n) = $Extract(s,m).
3. m < n '> $Length(s)br> $Extract(s,m,n) = $Extract(s,m) concatenated with $Extract(s,m+1,n).
   That is, using the concatenation operator _ of 7.2.1.1,
   $Extract(s,m,n) = $Extract(s,m)_$Extract(s,m+1)_..._$Extract(s,m+(n-m))
4. m < n and $Length(s) < n
   $Extract(s,m,n) = $Extract(s,m,$Length(s))

Copyright © Standard Documents; 1977-2024 MUMPS Development Committee;
Copyright © Examples: 1995-2024 Ed de Moel;
Copyright © Annotations: 2003-2008 Jacquard Systems Research
Copyright © Annotations: 2008-2024 Ed de Moel.

Some specifications are "approved for inclusion in a future standard". Note that the MUMPS Development Committee cannot guarantee that such future standards will indeed be published.

This page most recently updated on 15-Nov-2023, 13:08:30.

For comments, contact Ed de Moel (demoel@jacquardsystems.com)