e124. expanding an array.txt

这里面包含了一百多个JAVA源文件

The length of an array cannot be changed. The closest thing to expanding an array is to create a larger one of the same type and copy the contents from the old array. 
    Object newArray = Array.newInstance(array.getClass().getComponentType(), Array.getLength(array)*2);
    System.arraycopy(array, 0, newArray, 0, Array.getLength(array));