Change Variable Value by List Number

Hello all.
I’m trying to change the values of variables based on whether a certain sprite in a list is being used in the Sprite Renderer:

using UnityEngine;
using System.Collections.Generic;

public class Answers : MonoBehavior
{
 public List<Sprite> exampleList = new List<Sprite>();
 public float valueToChange;
 public int ID;
 private Rigidbody2D rb;
 private SpriteRenderer sr;

 void Start()
 {
  rb = GetComponent<Rigidbody2D>();
  sr = GetComponent<SpriteRenderer>();
  exampleList[ID] = sr.sprite;
 }

 void FixedUpdate();
 {
  if (sr.sprite = exampleList[0])
   valueToChange = 3.2f;
   rb.mass = 1.5f;
  if (sr.sprite = exampleList[1])
   valueToChange = 6.1f;
   rb.mass = 0.3f;
  //... and so on
 }
}

The issue I’m having is that this always returns the last sprite in the list and uses its values, regardless of what I set the ID value to.
I’m still very much a beginner so it might be that I’m just overlooking something.
Thanks!

try changing your if statements to use two equals signs. A single equals sign is an assignment, two equals signs are a comparison.

i.e.
if (sr.sprite == exampleList[0])

-Larry