[javascript] How to select first child with jQuery?

Use the :first-child selector.

In your example...

$('div.alldivs div:first-child')

This will also match any first child descendents that meet the selection criteria.

While :first matches only a single element, the :first-child selector can match more than one: one for each parent. This is equivalent to :nth-child(1).

For the first matched only, use the :first selector.

Alternatively, Felix Kling suggested using the direct descendent selector to get only direct children...

$('div.alldivs > div:first-child')