for {set sum 0; set counter 0} {$counter < 10} {incr sum $counter; incr counter} {} It's amusing how that pattern was adopted in Javascript (well, C/Jav

for {set sum 0; set counter 0} {$counter < 10} {incr sum $counter; incr counter} {} It's amusing how that pattern was adopted in Javascript (well, C/Java really I guess) as an optimisation. for (var sum = 0, counter = 0; counter < 10; sum = counter++) {}