string cat

string cat ?arg? ?arg …?

Returns the concatenation of its arguments in the order that they are given. If there are no arguments, produces the empty string. Does not produce errors.

First entered Tcl in 8.6.2.

Specified in TIP #429 .

A pure-Tcl proof of concept using ensemble extend:

extend string {
    proc cat args {
        join $args ""

'string cat' acts as the identity function for a single argument (see also: K). For multiple arguments, it concatenates them with no further substitution.