Casting in java.md

Casting in Java

Casting in Java is a process of converting one data type into another data type. This can be broadly classified into two types: Widening (Implicit) Casting and Narrowing (Explicit) Casting.

Widening (Implicit) Casting

Widening casting is when you convert a smaller data type to a larger data type. This is done automatically by Java and does not lead to loss of data.

Example:

public class CastingsInJava {
    public static void main(String[] args) {
        int num2 = 100;
        double num3 = num2; // Implicit casting - converting int to double
        System.out.println("Double value: " + num3); // Output: Double value: 100.0
    }
}

In the above example, the integer num2 is implicitly cast to a double num3 without any loss of data.

Narrowing (Explicit) Casting

Narrowing casting is when you convert a larger data type to a smaller data type. This needs to be done manually by placing the type in parentheses before the value. It may lead to loss of data because of truncation.

Example:

public class CastingsInJava {
    public static void main(String[] args) {
        double price1 = 100.50;
        int finalprice1 = (int) price1 + 18; // Explicit casting - converting double to int
        System.out.println("Final Price: " + finalprice1); // Output: Final Price: 118
    }
}

In this example, the double price1 is explicitly cast to an integer finalprice1, resulting in the truncation of the decimal part.

Int to String Conversion

Example

public class CastingsInJava {
    public static void main(String[] args) {
        int num = 100;
        String str = Integer.toString(num) + 10;
        System.out.println("String value: " + str); // Output: String value: 10010
    }
}

To convert an integer to a string, you can use the Integer.toString() method. In this example, the integer num is converted to a string and concatenated with 10.

String to Int Conversion

Example

public class CastingsInJava {
    public static void main(String[] args) {
        String str1 = "100";
        int num1 = Integer.parseInt(str1) + 10;
        System.out.println("Int value: " + num1); // Output: Int value: 110
    }
}

To convert a string to an integer, you can use the Integer.parseInt() method. In this example, the string str1 is parsed to an integer num1 and added to 10.

Summary

Casting is an essential concept in Java programming. Understanding the differences between implicit and explicit casting, and how to perform type conversions, is crucial for effective Java programming.

public class CastingsInJava {
    public static void main(String[] args) {
        double price = 100.50;
        double finalprice = price + 18; // Implicit casting - converting int to double
        System.out.println("Final Price: " + finalprice);

        int num2 = 100;
        double num3 = num2; // Implicit casting - converting int to double
        System.out.println("Double value: " + num3);

        double price1 = 100.50;
        int finalprice1 = (int) price1 + 18; // Explicit casting - converting double to int
        System.out.println("Final Price: " + finalprice1);

        int num = 100;
        String str = Integer.toString(num) + 10;
        System.out.println("String value: " + str);

        String str1 = "100";
        int num1 = Integer.parseInt(str1) + 10;
        System.out.println("Int value: " + num1);
    }
}