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Java collection/map apply方法等效吗?

在Java中,CollectionMap接口提供了一些方法,例如apply方法,它们在某些情况下可能具有等效性。

apply方法是Java 8中引入的,它允许您将函数应用于集合中的每个元素,并返回一个新的集合。在某些情况下,apply方法可能与其他方法具有等效性,例如forEach方法。

以下是一些示例:

代码语言:java
复制
List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5);

// 使用 apply 方法
List<Integer> doubledNumbers = numbers.stream()
    .map(number -> number * 2)
    .collect(Collectors.toList());

// 使用 forEach 方法
List<Integer> doubledNumbers2 = new ArrayList<>();
numbers.forEach(number -> doubledNumbers2.add(number * 2));

在这个例子中,apply方法和forEach方法都可以实现相同的功能,即将集合中的每个元素乘以2。

然而,需要注意的是,apply方法和其他方法的等效性可能会因具体情况而异。在某些情况下,apply方法可能比其他方法更适合,例如当您需要将函数应用于流时。

总之,apply方法在Java中可能具有等效性,但具体取决于您的需求和上下文。

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