Java Arrays常用函数

• copyOfRange

public static int[] copyOfRange(int[] original, int from, int to) {
        int newLength = to - from;
        if (newLength < 0)
            throw new IllegalArgumentException(from + " > " + to);
        int[] copy = new int[newLength];
        System.arraycopy(original, from, copy, 0,
                         Math.min(original.length - from, newLength));
        return copy;
    }

-  内部实现实际是调用了System.arraycopy数组拷贝方法
- Math.min(original.length - from, newLength)这行代码表示，若拷
 贝的内容超出源数组的数组边界，则只拷贝from位置到源数组最后一个元素，防
 止 数组越界