Jquery finding firrt element of specific class

I am using jquery to find a first element having a class "error" applied to it using the below code

$('#mainDiv input.error:eq(0)')

But the above one working only for input elements only. How to make this on开发者_Python百科e to work for both input and select elements?

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$('#mainDiv .error:eq(0)')

or

$('input.error, select.error', '#mainDiv').first()

if you want to find only input and select objects