--- /dev/null
+/**
+ * Used by `_.trim` and `_.trimRight` to get the index of the last character
+ * of `string` that is not found in `chars`.
+ *
+ * @private
+ * @param {string} string The string to inspect.
+ * @param {string} chars The characters to find.
+ * @returns {number} Returns the index of the last character not found in `chars`.
+ */
+function charsRightIndex(string, chars) {
+ var index = string.length;
+
+ while (index-- && chars.indexOf(string.charAt(index)) > -1) {}
+ return index;
+}
+
+module.exports = charsRightIndex;