How do I insert an object in an array?

Question

How can I insert an object in an array of variable size?
I input two numbers from keyboard
1
2that form the following object (Pair)
(1,2)
how can I add such objects to an array
private Pair s[];
e.g.
public PairList(int x){
top = -1;
s = new Pair[x];
}//constructor
public void getPairs()throws FullException{
BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
try{
a=input.readLine();b=input.readLine();
}//try
catch(IOException e){System.out.println("Can't read input");}//catch
int x=0;
int y=0;
try{
x=Integer.parseInt(a);}//try
catch(NumberFormatException e){}
try{
y=Integer.parseInt(b);}//try
catch(NumberFormatException e){}
Pair k=new Pair(x,y);
System.out.println(k);
s[++top]=k; --here is my problem
}//getPairs

Answer 1

I tried making as few changes to your code as possible, but your idea should basically work. Potential problems:
1. Doesn't allow for more input than 1 pair.
2. By storing pair in an array, you must know the exact size of the array you will need beforehand. You might be better off storing the Pair(s) in a Vector and then converting that to an array.
3.Your exception handlers need some work. Basically, your exception handlers put out a message or do nothing and then you continue processing. Not good.
4. No cleanup of file resources after you have completed
import java.io.*;
public class PairList{
     private Pair s[];
     private int top;
     public PairList(int x){
          top = -1;
          s = new Pair[x];
     }//constructor
     public void getPairs()throws Exception{
          BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
          String a = null, b = null;
          try{
               a=input.readLine();
               b=input.readLine();
          }//try
          catch(IOException e){
               System.out.println("Can't read input");
          }//catch
          int x=0;
          int y=0;
          try{
               x=Integer.parseInt(a);
          }//try
          catch(NumberFormatException e){
          try{
               y=Integer.parseInt(b);}//try
          catch(NumberFormatException e){
          Pair k=new Pair(x,y);
          System.out.println(k.toString());
          s[++top]=k; //here is my problem
     }//getPairs
class Pair {
     private int xx;
     private int yy;
     public Pair(int x, int y) {
          xx = x;
          yy = y;
     public String toString() {
          return("X = " + xx + "  Y = " + yy);
}