Here you can find the source of length(final T[]... arrays)
public static <T> int length(final T[]... arrays)
//package com.java2s; public class Main { public static <T> int length(final T[]... arrays) { int length = 0; for (T[] array : arrays) { if (array != null) length += array.length;/*from w w w .j a v a2 s .c o m*/ } return length; } }