How to sort array in ng-options by key?

问题

There is such array:

month: Array[13]0: "M"1: "January"2: "February"3: "March"4: "April"5: "May"6: "June"7: "July"8: "August"9: "September"10: "October"11: "November"12: "December"

I do:

ng-options="key as value for (key, value) in data.month | orderBy:key"

But I get unsorted select list.

回答1:

In order to use tracking with filters use track by.

Markup

ng-options="key as value for (key, value) in data.month | orderBy:'key' track by key"

Update

This orderBy will never work because you are having literal array. You need to convert this array to JSON like object which would structured like [{id: 0, value: "M"}, {id: 1, value: "January"},......]

HTML

ng-options="item.id as item.value for items in data.month | orderBy:'id'"

Demo Plunkr

回答2:

Your missing two ''s. This part, orderBy: key should be orderBy:'key'

Try this:

ng-options="key as value for (key, value) in data.month | orderBy: 'key'"

回答3:

To resolve this issue need reformat ng-option like as:

day.id as day.value for day in data.month

And array data.month would be how as told user pankajparkar

来源：https://stackoverflow.com/questions/30621053/how-to-sort-array-in-ng-options-by-key