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Tcl/Tk Documentation > TclCmd > concat

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NAME

concat - Join lists together

SYNOPSIS

concat ?arg arg ...?

DESCRIPTION

This command joins each of its arguments together with spaces after trimming leading and trailing white-space from each of them. If all the arguments are lists, this has the same effect as concatenating them into a single list. It permits any number of arguments; if no args are supplied, the result is an empty string.

EXAMPLES

Although concat will concatenate lists (so the command:

concat a b {c d e} {f {g h}}

will return "a b c d e f {g h}" as its result), it will also concatenate things that are not lists, and hence the command:

concat " a b {c   " d "  e} f"

will return "a b {c d e} f" as its result.

Note that the concatenation does not remove spaces from the middle of its arguments, so the command:

concat "a   b   c" { d e f }

will return "a b c d e f" (i.e. with three spaces between the a, the b and the c).

SEE ALSO

append, eval

KEYWORDS

concatenate, join, lists