Package

package pack1; 
public class MathOperation { 
public int add(int a,int b){ 
return a+b; 
} 
public int subtact(int a,int b){ 
return a-b; 
} 
}

package pack2; 
public class StringOperation { 
String CatStr,RevStr=""; 
public String concatenate(String a,String b){ 
CatStr = a+" "+b; 
return CatStr; 
} 
public String reverse(String str){ 
char ch[] = str.toCharArray(); 
int strlen = str.length(); 
for(int i=strlen-1;i>=0;i--){ 
RevStr=RevStr+ch[i]; 
} 
return RevStr; 
} 
}

package pack3; 
class UDException extends Exception{ 
public UDException(String message){ 
super(message); 
} 
} 
public class calculator { 
double div; 
public int multiply(int a,int b){ 
return a*b; 
} 
public double divide(double a,double b){ 
try{ 
if(b==0){ 
throw new Exception("Do not enter 0 as denominator."); 
} 
else{ 
div=a/b; 
} 
} 
catch(Exception e){ 
System.out.println(e.getMessage()); 
} 
return div; 
} 
}







// Distance converter
// Create a package named "converter"
package converter;

// Create a class named "DistanceConverter" in the "converter" package
public class DistanceConverter {

    // Method to convert meters to kilometers
    public static double metersToKilometers(double meters) {
        return meters / 1000.0;
    }

    // Method to convert miles to kilometers
    public static double milesToKilometers(double miles) {
        return miles * 1.60934;
    }

    // Method to convert kilometers to miles
    public static double kilometersToMiles(double kilometers) {
        return kilometers / 1.60934;
    }

    // Method to convert kilometers to meters
    public static double kilometersToMeters(double kilometers) {
        return kilometers * 1000.0;
    }
}





// Create a package named "main"
package main;

// Import the "converter" package to use the DistanceConverter class
import converter.DistanceConverter;

public class Main {

    public static void main(String[] args) {
        // Example conversions
        double meters = 1000.0;
        double miles = 10.0;

        // Convert meters to kilometers
        double metersToKm = DistanceConverter.metersToKilometers(meters);
        System.out.println(meters + " meters is equal to " + metersToKm + " kilometers");

        // Convert miles to kilometers
        double milesToKm = DistanceConverter.milesToKilometers(miles);
        System.out.println(miles + " miles is equal to " + milesToKm + " kilometers");

        // Convert kilometers to miles
        double kmToMiles = DistanceConverter.kilometersToMiles(metersToKm);
        System.out.println(metersToKm + " kilometers is equal to " + kmToMiles + " miles");
    }
}