Hi Friend,

Try the following code:

import java.util.*;
import java.text.*;

public class Computer{
String name;
int size;
int speed;
String make;
double price;
double quantity;

DecimalFormat f = new DecimalFormat("##,###");
public Computer(String n,int s,int sp,String m,double p,double q){
this.name=n;
this.size=s;
this.speed=sp;
this.make=m;
this.price=p;
this.quantity=q;
}
public void valid(){
if((price==0)||(price<0)){
System.out.println("Please enter valid price");
System.exit(0);
}
else if((quantity==0)||(quantity<0)){
System.out.println("Please enter valid quantity ");
System.exit(0);
}
else{
displayData();
}
}
public void displayData(){
StringBuffer buff = new StringBuffer();
buff.append("Computer Name : "+name);
buff.append("\nRAM Size : "+size);
buff.append("\nProcessor Make : "+make);
buff.append("\nProcessor speed : "+speed);
buff.append("\nQuantity : "+quantity);
buff.append("\nTotal Price of Computers : "+f.format(quantity * price));
buff.append("\n");
System.out.println(buff.toString());
}
public static void main(String[]args){
String name;
int size;
int speed;
String make;
double price;
double quantity;
System.out.println("Enter details");
Computer data[]=new Computer[2];
Scanner input=new Scanner(System.in);
for(int i=0;i<2;i++){
System.out.print("Computer Name: ");
name=input.next();
System.out.print("RAM Size: ");
size=input.nextInt();
System.out.print("Processor Speed: ");
speed=input.nextInt();
System.out.print("Processor Make: ");
make=input.next();
System.out.print("nQuantity: ");
quantity=input.nextDouble();
System.out.print("Price: ");
price=input.nextDouble();
Computer c=new Computer(name,size,speed,make,price,quantity);
data[i]=c;
System.out.println("\n*************************************");
}
for(int i=0;i<2;i++){
data[i].valid();
}
}
}

Hope that it will be helpful for you.
Thanks