可空布尔值的检查是如何工作的？

let nullableBoolean: boolean | null = null;

if (nullableBoolean === true) {
  console.log("The value is true.");
} else if (nullableBoolean === false) {
  console.log("The value is false.");
} else {
  console.log("The value is null or undefined.");
}

Boolean nullableBoolean = null;

if (nullableBoolean != null && nullableBoolean) {
  System.out.println("The value is true.");
} else if (nullableBoolean != null && !nullableBoolean) {
  System.out.println("The value is false.");
} else {
  System.out.println("The value is null.");
}

bool? nullableBoolean = null;

if (nullableBoolean.HasValue)
{
    if (nullableBoolean.Value)
    {
        Console.WriteLine("The value is true.");
    }
    else
    {
        Console.WriteLine("The value is false.");
    }
}
else
{
    Console.WriteLine("The value is null.");
}