Wrapper classes

There are 8 wrapper classes, all of which are part of java.lang. 

Double.parseDouble("23.5"); // 23.5
Double.parseDouble("23F"); // Run-time error

Autoboxing and unboxing

Integer.MIN_VALUE (Smallest integer value)
Integer.MAX_VALUE (Max integer value)

int val = 12;
Integer valObj = new Integer(val);

valObj.doubleValue(); // 12.0

Integer.parseInt("12"); // 12

Autoboxing: 
Integer valObj = 12; // Autoboxing
// int val = valObj.intValue(); 
int val = valObj; // Unboxing 
----------------------------------------------- Chapter 3 end

"One code a day will keep the doctor away" - COE211

Chapter 4: Writing classes

Objective: 
Die class - Helper class
Main class - Driver class

API - Application Programming Interface
CRUD (Create - Read - Update - Delete)

Signature for length() of String: 
int length()

nextLine() of Scanner: 
String nextLine()

nextInt(int upper) of Random: 
int nextInt(int upper)

Test Driven Development (TDD)






















