--- /dev/null
+
+
+ /**
+ * Array.indexOf
+ */
+ function indexOf(arr, item, fromIndex) {
+ fromIndex = fromIndex || 0;
+ if (arr == null) {
+ return -1;
+ }
+
+ var len = arr.length,
+ i = fromIndex < 0 ? len + fromIndex : fromIndex;
+ while (i < len) {
+ // we iterate over sparse items since there is no way to make it
+ // work properly on IE 7-8. see #64
+ if (arr[i] === item) {
+ return i;
+ }
+
+ i++;
+ }
+
+ return -1;
+ }
+
+ module.exports = indexOf;
+