// Lets say you have an object with tha name of 'Role' nad it has parameters
// 'Name' & 'Id'

List<Role> roles = new List<Role>();
roles.Add(new Role() { Name = "Admin", Id = 1 });
roles.Add(new Role() { Name = "User", Id = 2 });

// Using a lambda expression we can find the index of a role
// with a specific text:

int roleIndex = roles.FindIndex(
	// Note that you can also use the index if youd like
	role => role.Name == "Admin"
);

// This can also be done using a variable from outside
// the lambda expression: 

string name = "Admin";
int roleIndex = roles.FindIndex(
	// Note that you can also use the index if youd like
	role => role.Name == "name
);

if (roleIndex > -1)
{
    Console.log($"Role {roles[roleIndex].Name} +
                was found at index {roleIndex}");
}