Java Arrays.sort（）方法需要1D数组，但我也可以传递2D数组，为什么我不能做int [] a = b（其中b是2D数组）？

I'm having difficulty understanding the concept that I can pass a 2D array to java's Arrays.sort() method.(I have seen the java docs, the sort method can take only 1D arrays)I'm having difficulty understanding the concept