Cast Operator in Java

What does Java's type conversion operator () do and how does it work?

The cast operator in Java is employed to convert between various data types.

Example

CastOperatorExpl.java

public class CastOperatorExpl {
   public static void main(String args[]) {
      double d1 = 21.9;
      int i1 = (int)d1;
      System.out.println(i1);
   }
}

Output:

Programmers use the cast operator to type cast, which is the process of switching from one state to another. The programmer does typecast while creating the program. Narrow Conversion is also referred to as typecasting. Because the requirements of the operations frequently force us to Cast huge datatype items into smaller datatype values. Large datatype values can also be divided into smaller datatype values, which is why Type Casting is sometimes known as Narrow Casting.

Syntax: () is Cast Operator

Example 1:

CastOperatorExpl1.java

// Java Program for Implementing Datatype Typecasting

// Adding classes for input and output
import java.io.*;
 
// Driver class
public class CastOperatorExpl1 {
 
    // Main  method
    public static void main(String args[])
    {
        // making an integer datatype declaration.
        int a1 = 6;
 
        // Large datatype casting
        double d1 = (double)a1;
 
        // Print and show the value that was cast.
        System.out.println(d1);
 
        // conversion for narrow casting.
        int d2 = (int)d1;
         
        // Display and print the narrow cast value.
        System.out.println(d2);
    }
}

Output:

Type casting is the process of converting a value by one primitive data type to the other.

In Java, there are two types of casting:

Widening Conversion (automatically): Casting is the process of changing smaller type into larger type size.

byte -> short -> char -> int -> long -> float -> double

Narrowing Casting (manually): reducing the size of a larger font.

double -> float -> long -> int -> char -> short -> byte

Widening Casting

Widening casting is carried out automatically when switching from one size type to another:

Example:

WideningExpl.java

public class WideningExpl {
  public static void main(String args[]) {
    int i1 = 10;
    double d1 = i1; // Automatic casting from integer datatype to double datatype
    System.out.println(i1);      // Outputs 10
    System.out.println(d1);   // Outputs 10.0
  }
}

Output:

10
10.0

Narrowing Casting

By adding the type in parentheses ahead of the value, the narrow casting must be done manually:

Example:

NarrowingExpl.java

public class NarrowingExpl {
  public static void main(String args[]) {
    double d1 = 9.89d;
    int i1 = (int) d1; // Manual casting from double datatype to integer datatype

    System.out.println(d1);   // Outputs 9.89
    System.out.println(i1);      // Outputs 9
  }
}

Output: