Java ArrayList 初始化

List thisRow = new ArrayList(10);

java.util.ArrayList.ArrayList(int initialCapacity)

ArrayList
public ArrayList(int initialCapacity)
Constructs an empty list with the specified initial capacity.
Parameters:
initialCapacity - the initial capacity of the list
Throws:
IllegalArgumentException - if the specified initial capacity is negative

这个构造方法是建立了初始容量为initialCapacity的List, 但它此时为空, size()是0.

import java.util.ArrayList;
import java.util.List;

public class ValidAnagram {
    public static void main(String[] args) {
        List<Integer> thisRow = new ArrayList<Integer>(10);
        System.out.println(thisRow.size());

        thisRow.add(1);
        System.out.println(thisRow.size());
    }
}