count the elements in string

问题

I have a string that has comma separated values. How can I count how many elements in the string separated by comma. e.g following string has 4 elements

string = "1,2,3,4";

回答1:

myString.split(',').length

回答2:

var mystring = "1,2,3,4";
var elements = mystring.split(',');
return elements.length;

回答3:

First split it, and then count the items in the array. Like this:

"1,2,3,4".split(/,/).length;

回答4:

All of the answers suggesting something equivalent to myString.split(',').length could lead to incorrect results because:

"".split(',').length == 1

An empty string is not what you may want to consider a list of 1 item.

A more intuitive, yet still succinct implementation would be:

myString.split(',').filter((i) => i.length).length

This doesn't consider 0-character strings as elements in the list.

"".split(',').filter((i) => i.length).length
0

"1".split(',').filter((i) => i.length).length
1

"1,2,3".split(',').filter((i) => i.length).length
3

",,,,,".split(',').filter((i) => i.length).length
0

来源：https://stackoverflow.com/questions/3065941/count-the-elements-in-string