History of Array.prototype.indexOf() Revision history for: English (US) Jul 19, 2016, 1:07:33 PM eduardoboucas Add "Return value" section as per Bug 1287421 Previous Jul 19, 2016, 12:52:55 PM eduardoboucas Add "Return value" section as per Bug 1287421 Previous Mar 29, 2016, 6:45:11 AM fscholz bug 1242043 Previous Mar 14, 2016, 2:58:47 AM fscholz clr review Previous Mar 11, 2016, 10:48:51 AM andela-abankole , not necessary before or word because the OR is just telling the reader what === can be called. The , before operator word not necessary Previous Dec 25, 2015, 9:24:12 AM fscholz add ES draft Previous Dec 18, 2015, 3:02:23 AM mrenty Technical review completed. Previous Dec 16, 2015, 10:00:00 AM JasonWoof capital O is the worst variable name ever. Replaced with lowercase o. Previous Dec 8, 2015, 8:05:43 AM mina86 Modified example to demonstrate effect of fromIndex argument. Previous Sep 22, 2015, 10:12:07 PM kavitshah8 updated the example to show the function works as expected