COMMAND
append - Append strings to variableUSAGE
- append varName ?value value value ...?
DESCRIPTION
This Tcl command appends all of the value arguments to the current value of variable varName. If varName doesn't exist, it is given a value equal to the concatenation of all the value arguments. This command provides an efficient way to build up long variables incrementally. For example, append a $b is much more efficient than set a $a$b, if $a is long.MAN PAGE
http://www.tcl.tk/man/tcl8.5/TclCmd/append.htmSEE ALSO
other string functions: stringsimilar functions for lists: concat, lappendEXAMPLES
Building a string of comma-separated numbers piecemeal using a loop. set var 0
for {set i 1} {$i<=10} {incr i} {
append var "," $i
}
puts $var
# Prints 0,1,2,3,4,5,6,7,8,9,10NOTE: The append command is a string command. If you want to play with lists, definitely use the concat or lappend commands
Is the result of an append of two lists a list as you might expect it?
(EE: No. The result of an append of two lists is a string, which, if it can form a valid list, will shimmer into list form next time it is treated as one.)
Here's an example of such a case:
Is the result of an append of two lists a list as you might expect it?
(EE: No. The result of an append of two lists is a string, which, if it can form a valid list, will shimmer into list form next time it is treated as one.)
set a [list a b c] set b [list 1 2 3] append a $b puts $aNote that the third element of this new list is not c, but c1. Does anyone know if there are cases where an append would result in something not a list?
Here's an example of such a case:
set l1 [list a {b c}]
set l2 [list {d e} f]
append l1 $l2
llength $l1RS: The intended functionality seems to me to be closer to concat. But if you wish to use append, just add an extra space to separate the parts:append l1 " " $l2
