unset(3tcl)

NAME

   unset - Delete variables

SYNOPSIS

   unset ?-nocomplain? ?--? ?name name name ...?
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DESCRIPTION

   This  command  removes  one or more variables.  Each name is a variable
   name, specified in any of the ways acceptable to the set command.  If a
   name  refers  to  an  element  of an array then that element is removed
   without affecting the rest of the array.  If  a  name  consists  of  an
   array  name  with  no  parenthesized  index,  then  the entire array is
   deleted.  The unset command returns an  empty  string  as  result.   If
   -nocomplain is specified as the first argument, any possible errors are
   suppressed.   The  option  may  not  be  abbreviated,   in   order   to
   disambiguate  it from possible variable names.  The option -- indicates
   the end of the options, and should be used if  you  wish  to  remove  a
   variable with the same name as any of the options.  If an error occurs,
   any variables after the named one causing the error  are  not  deleted.
   An  error can occur when the named variable does not exist, or the name
   refers to an array element but the variable is a scalar,  or  the  name
   refers to a variable in a non-existent namespace.

EXAMPLE

   Create an array containing a mapping from some numbers to their squares
   and remove the array elements for non-prime numbers:
          array set squares {
              1 1    6 36
              2 4    7 49
              3 9    8 64
              4 16   9 81
              5 25  10 100
          }

          puts "The squares are:"
          parray squares

          unset squares(1) squares(4) squares(6)
          unset squares(8) squares(9) squares(10)

          puts "The prime squares are:"
          parray squares

SEE ALSO

   set(3tcl), trace(3tcl), upvar(3tcl)

KEYWORDS

   remove, variable

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