Java Type Casting

Type casting in Java is the process of converting a variable from one type to another. This is essential for ensuring that your program functions correctly with various data types. Below is an overview of the key concepts related to type casting in Java.

Key Concepts

1. Primitive Types

• Java has several primitive data types such as int, char, float, double, etc.
• Type casting can occur between these primitive types.

2. Types of Type Casting

There are two primary types of type casting in Java:

a. Widening Casting (Implicit)

• This is done automatically by the Java compiler.
• It converts a smaller type to a larger type without data loss.
• Example:

int num = 10;
double dNum = num; // int to double

b. Narrowing Casting (Explicit)

• This requires a cast operator and is performed manually.
• It converts a larger type to a smaller type, which may result in data loss.
• Example:

double dNum = 9.78;
int num = (int) dNum; // double to int

3. Casting Objects

Type casting can also be applied to objects, particularly in the context of inheritance.

• Upcasting: Casting a subclass object to a superclass reference (implicit).
• Downcasting: Casting a superclass reference back to a subclass reference (explicit).
• Example:

class Animal {}
class Dog extends Animal {}

Animal animal = new Dog(); // Upcasting
Dog dog = (Dog) animal; // Downcasting

Summary

• Type casting allows for the conversion of variable types in Java, which is essential for effectively working with different data types.
• Widening casting occurs automatically, while narrowing casting requires explicit declaration.
• Object casting pertains to inheritance and involves both upcasting and downcasting.

Understanding type casting is crucial for manipulating data and ensuring type compatibility in your Java applications!