man join () - Create a string by joining together list elements
NAME
join - Create a string by joining together list elements
SYNOPSIS
join list ?joinString?
DESCRIPTION
The list argument must be a valid Tcl list. This command returns the string formed by joining all of the elements of list together with joinString separating each adjacent pair of elements. The joinString argument defaults to a space character.
EXAMPLES
Making a comma-separated list: set data {1 2 3 4 5} join $data ", " => 1, 2, 3, 4, 5
Using join to flatten a list by a single level: set data {1 {2 3} 4 {5 {6 7} 8}} join $data => 1 2 3 4 5 {6 7} 8
SEE ALSO
KEYWORDS
element, join, list, separator