Array-part4.txt

                Array Variable Assignment
Element level promotions are applicable at array level.
For example: char element can be promoted to int type whereas char array cannot be promoted to int array.
int[] x = {1,2,3,4,5};
char[] ch = {'a','b','c','d'};

int[] b = x;  //valid
int[] ch = ch; //invalid compile-time-error : incompatible types: found:char[] required:int[];

Which one is valid & invalid??
char==>int //valid
char[]==>int[] //invalid
int==>double //valid
int[]==>double[] //invalid
float==>int //invalid
float[]==>int[] //invalid
String[]==>object //valid
String[]==>Object[] //valid

CASE A:
Child type array can be promoted to parent type array.
int or double type array can be converted to number type array

CASE B:
whenever we are assigning one array to another array, internal elements won't be copied, just reference variables will be re-assigned.
int[] a ={1,2,3,4,5};
int[] b = {7,8};
a=b; //valid
b=a; //valid

CASE C:
Whenever we are assigning one array to another array, the dimensions must be matched.
For example: in the place of one-dimensional int array, we should provide one dimensional array only.
If we are trying to provide any other dimension, then we will get compile-time-error.
int[][] a = new int[3][];
a[0] = new int[4][3] //invalid compile-time-error comes as incompatible types,found int[][] required int[]
a[0]= 10 //invalid compile-time-error comes as incompatible types,found int required int[]
a[0]=new int[2] //valid 

Whenever we are assigning one array to another array , both dimensions and types must be matched, but sizes are not required to match.