Ruby三元运算符（如果不是）

Question

How would you make this ternary?

if @user.skill.present?
    @skill = @user.skill
else
    @skill = Skill.new
end 

Answer 1

@skill = @user.skill || Skill.new

如果@ user.skill的值为零，它将把下一个值（Skill.new）分配给@skill。

Answer 2

I'd use:

@skill = @user.skill.present? ? @user.skill : Skill.new

However, ternery statements aren't often an improvement in readability/maintainability. They also don't improve processing speed. And they're frowned upon in some Ruby code shops and coding styles because they're too easily abused/misused.

Using if / else is entirely appropriate in this case so don't be afraid to go that route. Consider this: If you write logic using a ternary operator, and need to add additional processing to a returned value, you'll have to switch to using regular if / else processing anyway, or you'll generate some horrible looking code that will reduce its readability.

Answer 3

你可以试试

@user.skill.present? ? @skill = @user.skill :  @skill = Skill.new

Answer 4

@skill = @user.skill.present? ? @user.skill : Skill.new

perhaps more readable as a two liner

@skill = @user.skill
if @skill.blank? @skill = Skill.new