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. 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