java how efficient is casting code example

Example 1: java type casting

// You can typecast to convert a variable of one data type to another.
// Wide Casting converts small data types to larger ones.
// Narrow Casting converts large data types to smaller ones.
// Java can automatically Wide Cast.
// Java will throw an error when trying to automatically Narrow Cast.
// This is because data is often lost when Narrow Casting.
// Narrow Casting must be done manually.

//Wide Cast:
int SomeNumber = 5;
double WideCastedNumber = (double)SomeNumber;

//Narrow Cast:
double SomeNumber = 5.39;
int NarrowCastedNumber = (int)SomeNumber;
//Note: The data that holds the decimal places will be lost!

Example 2: casting in java

Primitive Type casting and Reference Type casting 
PRIMITIVE CASTING:
implicit casting (casting smaller type to larger
int a = 100; double c = a;) 
explicit casting (casting larger to smaller  
byte b = (byte) a; 
REFERENCE CASTING: 
upcasting - implicitly done (casting smaller type to larger)
Collection<Integer> collection = new ArrayList<>(); 
downcasting (cast larger type to smaller one )
List <Integer> list = ( ArrayList ) collection;
FRAMEWORK EXAMPLE:
Up Casting, Down Casting in Multi Browser testing. 
WebDriver, Chrome Driver, Firefox Driver object 
I casted to WebDriver to making reference type. 
Whenever you taking Screenshots, 
whenever executing Java script command.