need more explanation about array length

Answer 1

it counts each (comma-separated) value inside your [bracket-closed] array!

Answer 2

the array.length method prints out the number of values you have in your array

Answer 3

Array is a collection of same type variables referred by the same name. Each element of array can be accessed via index. In Java, array index always integer starting from 0. Here is a picture to illustrate an array... http://javabasictoadvanced.blogspot.co.id/2016/05/array.html