[habith]

> Older IEs don't have Array.indexOf()

IE8 and older to be specific[0]. But, if you're supporting IE8 still you have bigger problems at hand.

Microsoft stopped supporting any version lower than IE11 as of January 12th of this year[1]. So unless all of those older IE machines are accessing an intranet (and only an intranet) their risk of being hit with malware is way higher than average.

For my clients I do a cursory IE9+ review, but if anything lower is a requirement then it's an additional fee to make a site work with it.

In a few months it'll be IE11+ and the same fee structure will apply to anything lower (I'm just waiting for IE10 to wind down a bit).

[0] http://caniuse.com/#search=array.indexof

[1] https://www.microsoft.com/en-us/WindowsForBusiness/End-of-IE...