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Optional is primarily intended for use as a method return type where there is a clear need to represent "no result," and where using null is likely to cause ...
public static <T> Optional<T> empty(). 空の Optional インスタンスを返します。 この Optional には値はありません。 APIのノート: これは一時的なものですが、 ...
2026/2/15 -The purpose of the class is to provide a type-level solution for representing optional values instead of null references. To get a deeper ...
2023/1/15 -To add named and optional parameters to Java, this project uses a Javac Compiler Plugin. The public API exposes an immutable AST that can be ...
2025/3/10 -In this article, we'll delve into the purpose of Optional, common pitfalls in its usage, new API enhancements, and detailed examples of various ...
2022/9/2 -* Indicates whether some other object is "equal to" this {@code Optional}. * The other object is considered equal if: * <ul>. * <li>it is also ...
A container object which may or may not contain a non-null value. If a value is present, isPresent() will return true and get() will return the value.
As a method return type, as an alternative to returning null to indicate that no value was available · To distinguish between "unknown" (for example, not present ...
2014/5/4 -The main design goal of Optional is to provide a means for a function returning a value to indicate the absence of a return value.
Android API Reference. Overview. Android Platform. Packages. API level. REL, 37.2, 37.1, 37, 36.1, 36, 35, 34, 33, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22 ...