switch with a single character

Can anyone explain the results from switch below when a single
charachter "E" is entered? It seems to work with letter S or N...

?switch
.
.
.

Warning:

      Beware of partial matching: an alternative 'E = foo' will match
      the first argument 'EXPR' unless that is named. See the examples
      for good practice in naming the first argument.

HTH,

Chuck

switch("East",West=1,East=2)  # Correct

[1] 2

switch("E",W=1,E=2) # Not so correct

[1] 1

switch("E",E=1,W=2) # Even stranger

[1] "E"

switch("S",N=1,S=-1) # Correct

[1] -1

Kind regards, Henrik

-- 
Henrik Andersson
Tullstorp 2526
28195 Vankiva
Sweden

Tel: +46 451 19149
Mobil: +46 763 406779

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Charles C. Berry                            (858) 534-2098
                                             Dept of Family/Preventive Medicine
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