Scroll to navigation

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





NAME


lappend - Append list elements onto a variable






SYNOPSIS


lappend varName ?value value value ...?








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. 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.






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), lassign(3tcl), lindex(3tcl), linsert(3tcl),
    llength(3tcl), lmap(3tcl), lpop(3tcl), lrange(3tcl), lremove(3tcl),
    lrepeat(3tcl), lreplace(3tcl), lreverse(3tcl), lsearch(3tcl), lset(3tcl),
    lsort(3tcl)






KEYWORDS


append, element, list, variable







  

    
    Tcl