Условный оператор
if (x === 5 || x === 7 || x === 10 ||x === 20) {
// run my code
}
Outrageous Osprey
if (x === 5 || x === 7 || x === 10 ||x === 20) {
// run my code
}condition ? consequent : alternative
var rand = new Random();
var condition = rand.NextDouble() > 0.5;
var x = condition ? 12 : (int?)null;
https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/operators/conditional-operatorbCondition1 && bCondition2