Question

How can polymorphism replace an if-else statement or Switch inside of a loop? In particular can it always replace an if-else? Most of the if-thens I use inside of loops are arithmetic comparisons. This question is spawned from this question.

int x; int y; int z;  while (x > y) {      if (x < z)      {          x = z;      } } 

How would this work with polymorphism?
NOTE: I wrote this in Java but am interested in this for any OOL.

Answer 1

Polymorphism usually replaces switch statements when each case corresponds to a different type. So instead of having:

public class Operator {     string operation;      public int Execute(int x, int y)     {          switch(operation)          {              case 'Add':                  return x + y;              case 'Subtract':                  return x - y;              case 'Multiply':                  return x * y;              case 'Divide':                  return x / y;              default:                  throw new InvalidOperationException('Unsupported operation');          }     } } 

you’d have:

public abstract class Operator {     public abstract int Execute(int x, int y); }  public class Add : Operator {     public override int Execute(int x, int y)     {         return x + y;     } }  // etc 

However, for the comparison type of decision you provided, polymorphism really doesn’t help.