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 doesn't 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