C#•3y ago

how to search for a value in a list

pretty stupid question but ive tried looking online and i cant seem to find the answer, im fairly sure im using an older .net

36 Replies

OliOP•3y ago

trying to do it on line 26

pip•3y ago

using System.Linq;
string valueThatImLookingFor = "this";
list.First(p => p.Value/*or whatever the member name is*/ == valueThatImLookingFor);

using System.Linq;
string valueThatImLookingFor = "this";
list.First(p => p.Value/*or whatever the member name is*/ == valueThatImLookingFor);

Unknown User•3y ago

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OliOP•3y ago

thanks alot what does p and first refer too

Pobiega•3y ago

p => p.Name == attackerName is a predicate - an anonymous function that takes in an instance of the type the list is generic over, and returns a bool. FirstOrDefault will return the first item that matches the predicate (it returns true), or default(T) if no items matched

OliOP•3y ago

thanks ill try it again cause i thought p.Name had to be p.name since in the class it was name

Pobiega•3y ago

yeah it has to match the casing of the property in the team_create class you really should be using properties instead of fields for Name etc, and use proper casing (PascalCase for classes, properties, methods - camelCase for local variables) C# doesn't have snake_case as an officially accepted casing read more at https://learn.microsoft.com/en-us/dotnet/csharp/fundamentals/coding-style/coding-conventions

OliOP•3y ago

im slightly confused i looked at the link and im still pretty lost

Pobiega•3y ago

Well, in coding, we create a lot of things - classes, variables, methods etc right?

OliOP•3y ago

yep

Pobiega•3y ago

How you name them is important.

OliOP•3y ago

ohh i get what you mean

Pobiega•3y ago

C# has a "naming convention" which is kind of a standard you should follow

OliOP•3y ago

i see

Pobiega•3y ago

so other people can easily read and understand your code

OliOP•3y ago

makes sense so just capitalise the first letter and stuff

Pobiega•3y ago

Thats the basics, yeah so team_create would become TeamCreate snake_case -> PascalCase

OliOP•3y ago

I see oops

Pobiega•3y ago

public string name; would become public string Name { get; set; } that turns it from a public field to a public property, which might seem pointless now but become important later 🙂

OliOP•3y ago

alr thanks where would i put that if that makers sense

Pobiega•3y ago

You'd just replace your existing field name with that

OliOP•3y ago

ohh i was looking in the wrong place

OliOP•3y ago

so like this

Pobiega•3y ago

Yep! That looks good

OliOP•3y ago

one last thing, what should i write in catch so that if the value isnt found in the list it goes back to try or do i use something else

OliOP•3y ago

@Pobiega i tried looking online i found stuff like break but i dont think that will help

Pobiega•3y ago

you'd need a loop for that try/catch is "do this, if an exception occurs inside the try, jump to catch"

OliOP•3y ago

ah i see i was trying to make it too complicated lol

OliOP•3y ago

sorry to keep asking but how would i convert it to a boolean

OliOP•3y ago

wait nvm i cant convert a search into a boolean

Pobiega•3y ago

you just wanna know if there was a match or not? Team1.Any(x => x.Name == P1Check) also, rename your Team1 to team1 :p its a parameter, they should be camelCased same with Check, P1Check etc anything declared inside the method is camelCase

OliOP•3y ago

checkP1 then

Pobiega•3y ago

sounds good but yeah, First (and FirstOrDefault) is for finding a match if you dont want the match returned, just wanna know if it exists, use .Any

OliOP•3y ago

thanks

pip•3y ago

i tend to use firstordefault, then checking if the value is null as my scuffed "exists" check. is Any just better by default from a functional / readability standpoint?

Pobiega•3y ago

Shorter, returns a bool And in some cases, like with SQL, it can optimize the query

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