Provided by: tcl8.6-doc_8.6.8+dfsg-3_all bug

NAME

       variable - create and initialize a namespace variable

SYNOPSIS

       variable name

       variable ?name value...?
_________________________________________________________________________________________________

DESCRIPTION

       This  command  is  normally  used  within  a  namespace eval command to create one or more
       variables within a namespace.  Each variable name is initialized with  value.   The  value
       for the last variable is optional.

       If a variable name does not exist, it is created.  In this case, if value is specified, it
       is assigned to the newly created variable.  If no value is specified, the new variable  is
       left  undefined.  If the variable already exists, it is set to value if value is specified
       or left unchanged if no value is given.  Normally, name is unqualified (does  not  include
       the  names  of  any  containing  namespaces),  and  the variable is created in the current
       namespace.  If name includes any namespace qualifiers, the  variable  is  created  in  the
       specified  namespace.  If the variable is not defined, it will be visible to the namespace
       which command, but not to the info exists command.

       If the variable command is executed inside a Tcl procedure,  it  creates  local  variables
       linked  to the corresponding namespace variables (and therefore these variables are listed
       by info vars.)  In this way the variable command resembles the  global  command,  although
       the global command resolves variable names with respect to the global namespace instead of
       the current namespace of the procedure.  If any values are given, they are used to  modify
       the values of the associated namespace variables.  If a namespace variable does not exist,
       it is created and optionally initialized.

       A name argument cannot reference  an  element  within  an  array.   Instead,  name  should
       reference  the  entire  array, and the initialization value should be left off.  After the
       variable has been declared, elements within the array can be set  using  ordinary  set  or
       array commands.

EXAMPLES

       Create a variable in a namespace:

              namespace eval foo {
                  variable bar 12345
              }

       Create an array in a namespace:

              namespace eval someNS {
                  variable someAry
                  array set someAry {
                      someName  someValue
                      otherName otherValue
                  }
              }

       Access variables in namespaces from a procedure:

              namespace eval foo {
                  proc spong {} {
                      # Variable in this namespace
                      variable bar
                      puts "bar is $bar"

                      # Variable in another namespace
                      variable ::someNS::someAry
                      parray someAry
                  }
              }

SEE ALSO

       global(3tcl), namespace(3tcl), upvar(3tcl)

KEYWORDS

       global, namespace, procedure, variable