☜ | ELSEM[UMPS] by Example | ☞ |
Introduced in the 1977 ANSI M[UMPS] language standard.
The most common If-Then-Else construction is:
If X=4 Set A=5
Else Set A=6
But
If X=4 Do SUB
Else Quit
may produce an unexpected result if the program assumes that the
value of $Test does not change within the subroutine
SUB.
If the code in the above example was intended as an If-Then-Else
construction, then it would be better to write it as:
Quit:X'=4 Do SUB
Open DEVICE::20 Else Write "..."
Quit
Don’t process any data when resources cannot be allocated.
Lock +^ABC:20 Else Write "..."
Quit
Don’t update while someone else is editing
If VAR=VALUE Lock ^NAME:TIMEOUT Set
X=1
Else Set X=2
In this case... it depends. In the case where the values of
VAR and VALUE are not equal, local variable
X will be set to 2, but in the case whare those two
variables do have the same value, the value of $Test may
become false if the time-out expires, in which case the
Else command will also allow X to be set to 2.
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.
The information in this page is
NOT authoritative and subject to be modified
at any moment.
Please consult the
appropriate (draft) language standard for an
authoritative definition.
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, 14:42:33.
For comments, contact Ed de Moel (demoel@jacquardsystems.com)