Return only text before last underscore in JavaScript string

Question

If I have a string like so:

var str = 'Arthropoda_Arachnida_Zodariidae_Habronestes_hunti';

How can I get just the first part of the string before the last underscore?

In this case I want just 'Arthropoda_Arachnida_Zodariidae_Habronestes'

Answer 1

Slice and lastIndexOf:

str.slice(0, str.lastIndexOf('_'));

Answer 2

Combining substr and lastIndexOf should give you what you want.

var str = "Arthropoda_Arachnida_Zodariidae_Habronestes_hunti";
var start = str.substr(0, str.lastIndexof("_"));
// -> "Arthropoda_Arachnida_Zodariidae_Habronestes"