TCL "join" command not merging list into single string

With the "join" command I've assumed tcl would merge a list of elements into a single string with delimiter.

However this is not what I see at my terminal. Also, without a delimiter it returns the same list of elements with a space in between although ideally it should merge them with no spaces

Example:

## Setting original string set A [list 1 2 3] % 1 2 3 puts [llength $A] % 3 ## Join list without delimiter set B [join $A] % 1 2 3 puts [llength $B] % 3 ## Join list with space delimiter (actual requirement) set C [join $A " "] % 1 2 3 puts [llength $C] % 3 ## Join list with comma delimiter (to also visibly check what happens to each element of list) set D [join $A ","] % 1, 2, 3 puts [llength $D] % 3 foreach item $D {puts $item} 1, 2, 3 

Not sure what is going wrong here. I am trying to set a variable as a single string "1 2 3"

Trying to merge all elements of a list into single string. However "join" returns the same list as initial but with delimiter added to each element of list (except last).

EDIT: On my new machine, the [join $A ","] is working correctly as 1,2,3 without spaces.

1 Answer

The highly unlikely bit is this:

set A [list 1 2 3] # ==> 1 2 3 set D [join $A ","] # ==> 1, 2, 3 

as when I put that into a fresh Tcl session I instead get a final output of 1,2,3 (and that's not behaviour anyone's planning to change). I'm guessing you have a stray space in there or have defined a custom version of join.