lappend — Append list elements onto a variable
lappend varName ?value value value ...?
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.
If varName indicate an element that does not exist of an array that has
a default value set, list that is comprised of the default value with all the
value arguments appended as elements will be stored in the array
element.
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.
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
list, lassign, ledit, lindex, linsert, llength, lmap, lpop, lrange, lremove, lrepeat, lreplace, lreverse, lsearch, lseq, lset, lsort
append, element, list, variable
Copyright © 1993 The Regents of the University of California.
Copyright © 1994-1996 Sun Microsystems, Inc.
Copyright © 2001 Kevin B. Kenny <kennykb(at)acm.org>. All rights reserved.