// A modification of iferror.cpp to incorporate if else statements 
// and compound statements (those enclosed by braces { }).  Also,
// an explanation of if and if else is at the bottom of this file.

#include<iostream.h>
#include<cmath>

void main() {

  int a,b;
  double x,y,z;

  cout << "Enter 2 integers: ";
  cin >> a >> b;

  if (a==b)
    cout << "Next time, enter two DISTINCT integers." << endl;
  else
    {
      x = 1./(a-b);
      cout << "1/(" << a << " - " << b << ") = " << x << endl;
    }

  cout << "Enter a real number: ";
  cin >> y;

  if (y<0)
    cout << "Next time, enter a NONNEGATIVE real number." << endl;
  else
    {
    z = sqrt(y);
    cout << "The square root of " << y << " is " << z << endl;
    }
}


// An if statement with syntax
// if (expression) statement;
// executes the statement if expression is true, and does
// nothing if the expression is false.

// A modification of this uses if and else: syntax is
// if (expression) statement1;
// else statement2;
// If the expression is true, then statement1 is executed; and if
// the expression is false, statement2 is executed.