while(!ok){
System.out.println("enter a number");
String s=reader.readLine();
ok=true;
try{
double d=Double.parseDouble(s);
}
catch (NumberFormatException e){
System.out.println("That is not a number!");
ok=false;
}
}
//
while(!ok){
System.out.println("enter a number");
String s=reader.readLine();
ok=true;
try{
double d=Double.parseDouble(s);
}
catch (NumberFormatException e){
System.out.println("That is not a number!");
ok=false;
}
}
//