--- /dev/null
+var filter = require('./filter');
+
+ function isValidString(val) {
+ return (val != null && val !== '');
+ }
+
+ /**
+ * Joins strings with the specified separator inserted between each value.
+ * Null values and empty strings will be excluded.
+ */
+ function join(items, separator) {
+ separator = separator || '';
+ return filter(items, isValidString).join(separator);
+ }
+
+ module.exports = join;
+