# IComparable error due to float
**URL:** https://discussions.unity.com/t/icomparable-error-due-to-float/147612
**Category:** Questions & Answers
**Created:** [August 31, 2015, 9:04pm UTC](https://discussions.unity.com/t/icomparable-error-due-to-float/147612 "2015-08-31T21:04:46Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@NightLucididty](https://discussions.unity.com/u/NightLucididty)
#### Post date: [August 31, 2015, 9:04pm UTC](https://discussions.unity.com/t/icomparable-error-due-to-float/147612/1 "2015-08-31T21:04:46Z")
I am writing a list for my game,
But as I need it to have a string and a float,
So I am using unity’s script in for this purpose but I want to use a float instead of unity’s use of an int, This is unity’s code with my changes in float’s but I am still getting the error:
> Assets/PlayerMovement.cs(9,14): error CS0738: `PlayerMovement' does not implement interface member `System.IComparable.CompareTo(PlayerMovement)’ and the best implementing candidate `PlayerMovement.CompareTo(PlayerMovement)' return type `float’ does not match interface member return type `int’
```
using UnityEngine;
using System.Collections;
using System; //This allows the IComparable Interface
//This is the class you will be storing
//in the different collections. In order to use
//a collection's Sort() method, this class needs to
//implement the IComparable interface.
public class PlayerMovement : IComparable
{
public string movementName;
public float timeOfMovement;
public PlayerMovement(string newMovementName, float newTimeOfMovement)
{
movementName = newMovementName;
timeOfMovement = newTimeOfMovement;
}
//This method is required by the IComparable
//interface.
public int CompareTo(PlayerMovement other)
{
if(other == null)
{
return 1;
}
//Return the difference in power.
return timeOfMovement - other.timeOfMovement;
}
}
```
How can I remove this error and still use floats in my list,
Thanks in advance,
NightLucidity
---
### Author:  [@Dave-Carlile](https://discussions.unity.com/u/Dave-Carlile)
#### Post date: [August 31, 2015, 9:06pm UTC](https://discussions.unity.com/t/icomparable-error-due-to-float/147612/2 "2015-08-31T21:06:35Z")
I think you’re misunderstanding the purpose of the [CompareTo](https://msdn.microsoft.com/en-us/library/system.icomparable(v=vs.110).aspx) function. It returns \< 0 if the current object should sort before the other object, \> 0 if it’s after, and 0 if they’re equal. The data type must be `int` because that’s the definition of the interface, and the data type has no relationship to any other data type in your class. It’s simply a way to return the relationship between two objects (-1, 0, +1).