Remove the last character from a string

First, I try without a space, rtrim($arraynama, ","); and get an error result.

Then I add a space and get a good result:

$newarraynama = rtrim($arraynama, ", ");

You can use substr:

echo substr('a,b,c,d,e,', 0, -1);
# => 'a,b,c,d,e'

An alternative to substr is the following, as a function:

substr_replace($string, "", -1)

Is it the fastest? I don't know, but I'm willing to bet these alternatives are all so fast that it just doesn't matter.