Question

The following Java program is NOT designed using class/object concept.

public class demo_Program4_non_OOP_design {
public static void main(String[] args) {
String bottle1_label="Milk";
float bottle1_volume=250;
float bottle1_capacity=500;
bottle1_volume=addVolume(bottle1_label, bottle1_volume,bottle1_capacity,200);
System.out.println("bottle label: " + bottle1_label +
", volume: " + bottle1_volume +
", capacity: " +bottle1_capacity);

String bottle2_label="Water";
float bottle2_volume=100;
float bottle2_capacity=250;
bottle2_volume=addVolume(bottle2_label, bottle2_volume,bottle2_capacity,500);
System.out.println("bottle label: " + bottle2_label +
", volume: " + bottle2_volume +
", capacity: " +bottle2_capacity);

}
public static float addVolume(String label, float bottleVolume, float capacity, float addVolume) {
if (bottleVolume + addVolume <= capacity)
{
bottleVolume = bottleVolume + addVolume;
}
else
{
bottleVolume = capacity;
System.out.println(label + " bottle is overfilled.");
}
return bottleVolume;
}
}

(Thinking in objects) Redesign the above Java program to meet the following requirements:
(1) Design a bottle class with
a. necessary data fields, constructors and methods.
b. toString() method is required for this bottle class.
(2) Write a test class(xxxx_Program4) to include a main() method that does the following steps in
order:
a. Create 1st bottle object with -- label: Milk, volume: 250, capacity: 500

b. Add volume 200 to 1st bottle object.
c. Print the 1st object’s information by calling toString() method.
d. Create 2nd bottle object with -- label: Water, volume: 100, capacity: 250

e. Add volume 500 to 2ndbottle object.

f. Print the 2nd object’s information by calling toString() method.
(3) The output should be like:
bottle label: Milk, volume: 450.0, capacity: 500.0
Water bottle is overfilled.
bottle label: Water, volume: 250.0, capacity: 250.0

(4) This Program assignment does not take any input from the keyboard.

Answer 1

The solution to the above problem in Java is as follows:-

Code-

//Declaration of class Bottle
class Bottle{
   String label;
   float volume;
   float capacity;
   //Constructor to initialize Bottle objects
   public Bottle(String l,float vol,float cap){
       label=l;
       volume=vol;
       capacity=cap;
   }
   //Add volume to bottle
   public void addVolume(float vol){
       if(volume+vol<=capacity)
           volume=volume+vol;
       else{
           volume=capacity;
           System.out.println(label+" bottle is overfilled");
       }
   }
   //Convert details of bottle to String output
   public String toString(){
       String output="Bottle label: "+label+", Capacity: "+capacity+", Volume: "+volume;
       return output;
   }
}
public class test_program4{
   public static void main(String[] args){
       Bottle b1=new Bottle("Milk",250,500); //Create 1st bottle object with -- label: Milk, volume: 250, capacity: 500
       b1.addVolume(200); // Add volume 200 to 1st bottle object.
       System.out.println(b1.toString());//Print the 1st object’s information by calling toString() method.
       Bottle b2=new Bottle("Water",100,250); //Create 2nd bottle object with -- label: Water, volume: 100, capacity: 250
       b2.addVolume(500); // Add volume 500 to 2ndbottle object.
       System.out.println(b2.toString());//Print the 2nd object’s information by calling toString() method.
   }
}

Code Screenshots-

Outputs-

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