As a TCL programmer, you are permitted to imagine "everything is a string". In most TCL implementations, though, your "strings" are stored as objects underneat

As a TCL programmer, you are permitted to imagine "everything is a string". In most TCL implementations, though, your "strings" are stored as objects underneath, and converted when necessary. So if you say: set foo [+ 1 2] incr foo 3 puts $foo the variable `$foo` will not be converted into a string until the last line.