efficient

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

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NAME

       lappend - Append list elements onto a variable

SYNOPSIS

       lappend varName ?value value value ...?
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DESCRIPTION

       This  command  treats  the  variable given by varName as a list and appends each of the value arguments to that list as a separate element,
       with spaces between elements.  If varName does not exist, it is created as a list with elements given by the value arguments.   Lappend	is
       similar	to append except that the values are appended as list elements rather than raw text.  This command provides a relatively efficient
       way to build up large lists.  For example, "lappend a $b" is much more efficient than "set a [concat $a [list $b]]" when $a is long.

EXAMPLE

       Using lappend to build up a list of numbers.
	      % set var 1
	      1
	      % lappend var 2
	      1 2
	      % lappend var 3 4 5
	      1 2 3 4 5

SEE ALSO

       list(3tcl), lindex(3tcl), linsert(3tcl), llength(3tcl), lset(3tcl), lsort(3tcl), lrange(3tcl)

KEYWORDS

       append, element, list, variable

Tcl																     lappend(3tcl)