asp.net core LINQ where clause

Question

I'm new to asp.net and learning from pluralsight and instructor uses this LINQ query which I can't understand .
public IEnumerable<Restaurant> GetRestaurantsByName(string name = null)
{
return from r in restaurants
where string.IsNullOrEmpty(name) || r.Name.StartsWith(name)
orderby r.Name
select r;
}
I can't understand the where part. What does it do especially the first part string.IsNullOrEmpty(name)

Answer 1

Hi,AbdullahDurrani-7930,

GetRestaurantsByName gets restaurants with name.Firstly you need to check if name is empty or null with string.IsNullOrEmpty(name),if it is null or empty,you only need to return all restaurants.If it is not null or empty,you need to get restaurants with name.So there is a || between string.IsNullOrEmpty(name) and r.Name.StartsWith(name).Only when name is not null or empty,it will check r.Name with r.Name.StartsWith(name).

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