相关疑难解决方法(0)

我记得,在Java 8之前,默认容量ArrayList是10.

令人惊讶的是,对default(void)构造函数的注释仍然说: Constructs an empty list with an initial capacity of ten.

来自ArrayList.java:

/**
 * Shared empty array instance used for default sized empty instances. We
 * distinguish this from EMPTY_ELEMENTDATA to know how much to inflate when
 * first element is added.
 */
private static final Object[] DEFAULTCAPACITY_EMPTY_ELEMENTDATA = {};

...

/**
 * Constructs an empty list with an initial capacity of ten.
 */
public ArrayList() {
    this.elementData = DEFAULTCAPACITY_EMPTY_ELEMENTDATA;
}