variable(3tcl)						       Tcl Built-In Commands						    variable(3tcl)

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NAME

       variable - create and initialize a namespace variable

SYNOPSIS

       variable ?name value...? name ?value?
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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 names-
       pace.  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 only links to variables in the global namespace.  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

Tcl									8.0							    variable(3tcl)