<HTML><HEAD><TITLE>Tcl Built-In Commands - variable manual page</TITLE></HEAD><BODY> <H3><A NAME="M2">NAME</A></H3> variable - create and initialize a namespace variable <H3><A NAME="M3">SYNOPSIS</A></H3> <B>variable </B>?<I>name value...</I>? <I>name </I>?<I>value</I>?<BR> <H3><A NAME="M4">DESCRIPTION</A></H3> This command is normally used within a <B>namespace eval</B> command to create one or more variables within a namespace. Each variable <I>name</I> is initialized with <I>value</I>. The <I>value</I> for the last variable is optional. <P> If a variable <I>name</I> does not exist, it is created. In this case, if <I>value</I> is specified, it is assigned to the newly created variable. If no <I>value</I> is specified, the new variable is left undefined. If the variable already exists, it is set to <I>value</I> if <I>value</I> is specified or left unchanged if no <I>value</I> is given. Normally, <I>name</I> is unqualified (does not include the names of any containing namespaces), and the variable is created in the current namespace. If <I>name</I> includes any namespace qualifiers, the variable is created in the specified namespace. If the variable is not defined, it will be visible to the <B>namespace which</B> command, but not to the <B><A HREF="../TkCmd/info.htm">info exists</A></B> command. <P> If the <B>variable</B> command is executed inside a Tcl procedure, it creates local variables linked to the corresponding namespace variables (and therefore these variables are listed by <B><A HREF="../TkCmd/info.htm">info locals</A></B>.) In this way the <B>variable</B> command resembles the <B><A HREF="../TkCmd/global.htm">global</A></B> command, although the <B><A HREF="../TkCmd/global.htm">global</A></B> command only links to variables in the global namespace. If any <I>value</I>s 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. <P> A <I>name</I> argument cannot reference an element within an array. Instead, <I>name</I> should reference the entire array, and the initialization <I>value</I> should be left off. After the variable has been declared, elements within the array can be set using ordinary <B><A HREF="../TkCmd/set.htm">set</A></B> or <B><A HREF="../TkCmd/array.htm">array</A></B> commands. <H3><A NAME="M5">SEE ALSO</A></H3> <B><A HREF="../TkCmd/global.htm">global</A></B>, <B><A HREF="../TkCmd/namespace.htm">namespace</A></B>, <B><A HREF="../TkCmd/upvar.htm">upvar</A></B> <H3><A NAME="M6">KEYWORDS</A></H3> <A href="../Keywords/G.htm#global">global</A>, <A href="../Keywords/N.htm#namespace">namespace</A>, <A href="../Keywords/P.htm#procedure">procedure</A>, <A href="../Keywords/V.htm#variable">variable</A> <HR><PRE> <A HREF="../copyright.htm">Copyright</A> © 1993-1997 Bell Labs Innovations for Lucent Technologies <A HREF="../copyright.htm">Copyright</A> © 1997 Sun Microsystems, Inc. <A HREF="../copyright.htm">Copyright</A> © 1995-1997 Roger E. Critchlow Jr.</PRE> </BODY></HTML>