Gentoo Linux and VIM worshiper, C developer, network protocol dissector implementer,socket/network programmer, recently entered the embedded world, hater of buzzwords and made up titles
Sure, but this one is pretty easy to demystify, luckily: tr/set1/set2/ just replaces characters in set1 with those in set2 (positionally), and returns the number of characters replaced/deleted. So in this code, he just compares the number of X's replaced with the number of O's replaced, and includes the lower-case variants too.
The local($_) is just there to let him make the code more brief. $_ is the "default input/pattern-searching space", so its like the default argument that tr will search. But it's also a global, so this lets you make a local copy and set it to be the first argument to the function.
If he didn't do that, it might look like this:
sub xo{my$xos=shift;($xos=~tr/xX//)==($xos=~tr/oO//)}
Perl sorcery 😁. This syntax always turns me inside out hehe. Nice job 👍
Sure, but this one is pretty easy to demystify, luckily:
tr/set1/set2/just replaces characters inset1with those inset2(positionally), and returns the number of characters replaced/deleted. So in this code, he just compares the number of X's replaced with the number of O's replaced, and includes the lower-case variants too.The
local($_)is just there to let him make the code more brief.$_is the "default input/pattern-searching space", so its like the default argument thattrwill search. But it's also a global, so this lets you make a local copy and set it to be the first argument to the function.If he didn't do that, it might look like this:
So just a bit more verbose.
Thanks for a great explanation :)