Array

Why arrays are special

effeciency type and can hold primitive

Items in Array are default initialized to NULL, and if it is a primitive array, 0 for char int float etc and false for boolean.

Java can directly return arrays, dislike C and C++, java return a reference. The garbage collector takes care of cleaning up the array.

Multidimensional Arrays

Creating test data

使用array时，我们最好都填好数据 Arrays.fill()

使用好Arrays utilities

Useful static method in Arrays

equals() compare two arrays for equality

deepEquals for multidimensional arrays

fill for fill data

sort sort an array

binarySearch find an element in a sorted array

asList takes any sequence or array and turn it into a List container

System.arraycopy is more quickly than use for loop if this copy for object, only reference copid, this is called shallow copy

Using Container instend, if you reaylly has Perfermence issue, using Array!