JavaScript deletes the last character of a string

The requirement is a string that wants to delete the last character of the string, such as "1,2,3,4,5," and delete the Last "," How do you implement it with JavaScript? Here are three different methods

Find a lot on the internet, summed up several methods for everyone's reference: 1, the most used is Substring, this is the code I have been using as follows: S=s.substring (0,S.LENGTH-1) 2, with RTrim, this I used to know only to delete the last space, also did not Have looked at other uses carefully, only then discovered can directly trim off some character code as follows: S=s.tostring (). RTrim (', ') 3, with trimend, this thing is similar to RTrim, the difference is that this pass is a character array, and RTrim can be any valid string code as follows: S=s.trimend (', ')//If you want to delete "5," You need to write Cha r[]mychar={' 5′, ', '}; S=s.trimend (MyChar); S= "1,2,3,4″