How to find out if an IList object contains a specific value anywhere in the list

Question

This code obviously doesn't work...but it's what I want to accomplish (Using IList)

if (this.Model.myOptionsList.Contains(SelectedOption.value)){

     do something
}

The contents of myOptionsList looks like this:

SelectedOption.value contains an Id...i.e. 34 I need to know if that exists in the myOptionsList.

The catch is that I need to do that on the Razor page because it won't be available in the controller.

Answer 1

There are many methods, two friends said. I say three other methods(Count, Exists, FirstOrDefault).

Exists(it is better):

if (this.Model.myOptionsList.Exists(d => d.Id == SelectedOption.value))
{
    // do something
 }

Count:

  if (this.Model.myOptionsList.Count(d => d.Id == SelectedOption.value) > 0)
  {
                // do something
  }

FirstOrDefault:

 if (this.Model.myOptionsList.FirstOrDefault(d => d.Id == SelectedOption.value) != null)
  {
                // do something
  }

also you can write if in two ways. The first method, if the condition is false, return; Next go to second part( // do something) way 1:

if (this.Model.myOptionsList.Count(d => d.Id == SelectedOption.value) == 0) return;

     //other
     // do something

way 2:

if (this.Model.myOptionsList.Count(d => d.Id == SelectedOption.value) == 0)
 {
    // do something
 }