programs :Lang_Util

Equals
public class Equals{
public static void main(String args[]){
    Calculator c1=new Calculator();
    Calculator c2=c1;//new Calculator();
    if(c1==c2){
       System.out.println("c1==c2");
    }else{
    System.out.println("c1!=c2");
    }
    if(c1.equals(c2)){
       System.out.println("c1.equals(c2)");
    }else{
      System.out.println(" c1 not equal to (c2)");
    }
}
}
hashCode
public class hashCode{
public static void main(String args[]){
    Calculator c1=new Calculator();
    Calculator c2=new Calculator();
        int i=c1.hashCode();
       System.out.println("c1.hashCode() : "+c1.hashCode());
       System.out.println("c2.hashCode() : "+c2.hashCode());
       Demo d=new Demo();
       System.out.println("this.hashCode() : "+d.hashCode());   
          System.out.println("Result : "+ c1.add(10,20));
       c1=c2;
       System.out.println("c1.hashCode() : "+c1.hashCode());
       System.out.println("c2.hashCode() : "+c2.hashCode());
       if(c1.hashCode()==i)
              System.out.println("Result : "+ c1.add(10,20));
       else
                 System.out.println("C1 is unknown Object");
}
}

PriEquals
public class PriEquals{
public static void main(String args[]){
    int c1=100;
    int c2=1000;
    if(c1==c2){
       System.out.println("c1==c2");
    }else{
    System.out.println("c1!=c2");
    }
    /*if(c1.equals(c2)){
       System.out.println("c1.equals(c2)");
    }else{
      System.out.println(" c1 not equal to (c2)");
    }*/
}
}