如果在数组中找不到项，请使用默认值

So I've got my code trying to select an object from an array of objects, and if the object isn't found, I want to create my defaults.

所以我的代码试图从一个对象数组中选择一个对象,如果找不到该对象,我想创建我的默认值。

lead_time = lead_times.select{|d| LeadTimeProfile.new unless d.day_of_week == day }

however, from what I can tell, this is not returning me the devault LeadTimeProfile.

但是,据我所知,这并没有让我失去了LeadTimeProfile。

is there a way of doing this? Or have I got it right?

有没有办法做到这一点?或者我做对了吗?

2 个解决方案

#1

So I've got my code trying to select an object from an array of objects, and if the object isn't found, I want to create my defaults.

所以我的代码试图从一个对象数组中选择一个对象,如果找不到该对象,我想创建我的默认值。

Take a look at Enumerable#find

看看Enumerable#find

lead_time = lead_times.find{ |d| d.day_of_week == day } || LeadTimeProfile.new

#2

filter your array first, and then do the construction

首先过滤你的数组,然后进行构造

lead_time = lead_times.select{|d| d.day_of_week == day}.map {|d| LeadTimeProfile.new(d)}

lead_time = lead_times.select {| d | d.day_of_week == day} .map {| d | LeadTimeProfile.new(d)}