lappend varName ?value value ...?
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http://www.purl.org/tcl/home/man/tcl8.4/TclCmd/lappend.htm
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Appends each ''value'' as a list [element] onto the end of the list stored in ''varName''. 

''lappend'' used to be the only list-command which requires the '''name of a variable containing a list''' rather than the list itself, but in Tcl 8.4 the [lset] command was introduced.

 lappend listName
rather than
 lappend $listName

This command differs from [append] in that values are appended as list elements rather than raw text.

lappend will not ''make'' varName a list ; if it is one before the command, it will continue to be one.

[AJD] Uh? [lappend] *will* attempt to make varName's value into a list. The docs say "This command treats the variable given by varName as a list." ie. if it isn't a list to begin with, tcl will attempt to convert it to one, giving an error this is not possible:
 % set x "a \{" ;# string
 a {
 % lappend x b ;# treat it as list
 unmatched open brace in list ;# it wasn't a proper list!


You do not need to assign the results of lappend to varName; lappend modifies varName directly.
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How would one append an item to the beginning of a list?
Since ''append'' means ''to the end of'', one wouldn't append to the beginning of a list.  Instead, for a way to perform the equivalent of ''prepend'', see [linsert] -- jfr

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[TV] ''(Oct 26 '04)'' Just because I happened to stumble accross this:

 (Tcl) 98 % set r {}
 (Tcl) 99 % lappend r {1 2}
 {1 2}
 (Tcl) 100 % set r {1 2}
 1 2


You "stumbled across" proper list quoting?  What?
The first $r is a list with one element: "1 2"
The second $r is a list with two elements: "1" and "2"
Exactly the way it is supposed to be.

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See also [list], [lindex], [linsert], [llength], [lrange], [lreplace], [lsearch], [lsort] .

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