string reverse , a subcommand of the built-in string command, reverses strings

Synopsis  edit

string reverse string

Description  edit

Returns a string containing the characters of its input argument, string, in reverse order.

Implemented in the Changes in Tcl/Tk 8.5, as part of TIP #272[1].

Workaround substitute for 8.4:

proc string'reverse str {
   set res {}
   set i [string length $str]
   while {$i > 0} {append res [string index $str [incr i -1]]}
   set res
} ;# RS
% string'reverse "hello, world"
dlrow ,olleh

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Implementation notes

This command converts its argument to the "unicode" object type so that it doesn't have to use Tcl_UtfPrev() masses of times.

See Also  edit

   [SYStems]:  contains a discussion on reversing strings

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