Double pipe (||) in AngularJS expressions

Question

On my controller, I have something like: this.user = { first_name: "David", full_name: "David Silva" }

The data I receive sometimes does not have a full_name, so I tried this expression: {{user.full_name || user.first_name}}

It seems to work, but after a more thorough study, I understand that it does not behave the way it will in normal JS. I expected that if full_name was undefined or empty, it will try to use another, but instead, if the expression after ||is valid, it will be evaluated this way, regardless of the expression on the left.

I could not understand why, and I would like to know more about how this is interpreted in order to use it correctly.

Answer 1

|| angularJS. , , . :

user.full_name ?  user.full_name : user.first_name

if(user.full_name)
    return user.full_name
else
    return user.first_name

, , , || .