最近在看ArrayList源码的时候看到了ArrayList的clear方法，源码如下：public void clear() {
modCount++;
// clear to let GC do its work
for (int i = 0; i < size; i++)
elementData[i] = nul
/**
* The array buffer into which the elements of the ArrayList are stored.
* The capacity of the ArrayList is the length of this array buffer.
*/
private transient Object[
ArrayList<String> al = newArrayList<String>();对于上述问题再熟悉不过了，但有没有考虑al的初始容量的问题的呢如果直接打印al.size()当然是1,但问题不是这样的。通过查看java.util.ArrayList类文件（在jre/rt.jar包里面）我用的是JDK7的版本，查看Arraylist构造函数如下：<pre n
