try{
  // do something with
  // potential thrown
  // exception.
} catch( exception ){
  // handle the error
}
double divide(double a, double b) {
  if(b==0)
    throw("Cannot divide by zero\n");
  return(a/b);
}
...
try{
  cout << divide(4,0);
} catch(const char* err) {
  cout << err << endl;
}