在Jquery中选择给定表单的所有输入

我在jquery中有一个表单对象，我想选择此表单的所有输入.

I have a form object in jquery, and I'd like to select all inputs of this form.

假设我的表单对象称为 form .如果表单有ID，我就可以

Let's suppose my form object is called form. If the form has an id, I can just do

var id = form.attr('id');
var inputs = $('#' + id + ' input');

如果没有，我可以检查一下，然后手动添加一个临时ID，进行选择，然后删除该ID(或仅将其保留在此处).但这看起来太复杂了，必须有一种更简单的方法，但是我找不到它.

If not I can check this, and then manually add a temporary id, do the selection, and remove the id (or just leave it there). But this just looks too complicated, there must be an easier way, but I'm not able to find it.

另一种可能的方式(我无法工作)类似于

Another possible way (which I'm not able to make work) would be something like

var inputs = $('input').filter(function() {
    var parents = this.parents();
    return ($.inArray(form, parents) != -1);
});

但是这看起来也很复杂(并且无法按规定进行操作).

but this too seems complicated (and it doesn't work as stated).

从性能的角度来看，哪种方法会更方便?

By the way, from the performance point of view, which approach would be more convenient?