transform.eulerAngles Flipping a character

Hi, I've been learning about this script for a few days, and I ran into something that is kind of confusing. It has to do with this line right here.

  // Face Direction
         float moveDir = Input.GetAxisRaw("Horizontal");
         if (moveDir !=0) {
             transform.eulerAngles = (moveDir>0)?Vector3.up * 180:Vector3.zero;
         }
 

I notice that if I set the Input to positive 1 then the character I am using has its rotation flipped i.e. if transform.eulerAngles = moveDir>0 then flip the character on the y axis 180 degrees, otherwise don't do anything/keep the vector at zero.

But it still works if I turn the other way (if the moveDir is less than zero), even if I didn't actual put any code in to tell it to. So am I missing something. Is this just the way the code works or transform.eulerAngles works?

 using UnityEngine;
 using System.Collections;
 
 [RequireComponent(typeof(PlayerPhysics))]
 public class PlayerController : MonoBehaviour {
     
     // Player Handling
     public float gravity = 20;
     public float walkSpeed = 8;
     public float runSpeed = 12;
     public float acceleration = 30;
     public float jumpHeight = 12;
     
     private float animationSpeed;
     private float currentSpeed;
     private float targetSpeed;
     private Vector2 amountToMove;
     
     private PlayerPhysics playerPhysics;
     private Animator animator;
     
 
     void Start () {
         playerPhysics = GetComponent<PlayerPhysics>();
         animator = GetComponent<Animator>();
     }
     
     void Update () {
         // Reset acceleration upon collision
         if (playerPhysics.movementStopped) {
             targetSpeed = 0;
             currentSpeed = 0;
         }
         
         // If player is touching the ground
         if (playerPhysics.grounded) {
             amountToMove.y = 0;
             
             // Jump
             if (Input.GetButtonDown("Jump")) {
                 amountToMove.y = jumpHeight;    
             }
         }
         
         // Set animator parameters
         animationSpeed = IncrementTowards(animationSpeed,Mathf.Abs(targetSpeed),acceleration);
         animator.SetFloat("Speed",animationSpeed);
         
         // Input
         float speed = (Input.GetButton("Run"))?runSpeed:walkSpeed;
         targetSpeed = Input.GetAxisRaw("Horizontal") * speed;
         currentSpeed = IncrementTowards(currentSpeed, targetSpeed,acceleration);
         
         // Set amount to move
         amountToMove.x = currentSpeed;
         amountToMove.y -= gravity * Time.deltaTime;
         playerPhysics.Move(amountToMove * Time.deltaTime);
         
         // Face Direction
         float moveDir = Input.GetAxisRaw("Horizontal");
         if (moveDir !=0) {
             transform.eulerAngles = (moveDir>0)?Vector3.up * 180:Vector3.zero;
         }
 
     }
     
     // Increase n towards target by speed
     private float IncrementTowards(float n, float target, float a) {
         if (n == target) {
             return n;    
         }
         else {
             float dir = Mathf.Sign(target - n); // must n be increased or decreased to get closer to target
             n += a * Time.deltaTime * dir;
             return (dir == Mathf.Sign(target-n))? n: target; // if n has now passed target then return target, otherwise return n
         }
     }
 }

&&

 using UnityEngine;
 using System.Collections;


 [RequireComponent (typeof(BoxCollider))]
 public class PlayerPhysics : MonoBehaviour {
 
 public LayerMask collisionMask;

 private BoxCollider collider;
 private Vector3 s;
 private Vector3 c;
 
 private Vector3 originalSize;
 private Vector3 originalCentre;
 private float colliderScale;
 
 private int collisionDivisionsX = 3;
 private int collisionDivisionsY =10;
 
 private float skin = .005f;
 
 [HideInInspector]
 public bool grounded;
 [HideInInspector]
 public bool movementStopped;
 
 Ray ray;
 RaycastHit hit;
 
 void Start() {
     collider = GetComponent<BoxCollider>();
     colliderScale = transform.localScale.x;
     
     originalSize = collider.size;
     originalCentre = collider.center;
     SetCollider(originalSize,originalCentre);
 }

 public void Move(Vector2 moveAmount) {
     
     float deltaY = moveAmount.y;
     float deltaX = moveAmount.x;
     Vector2 p = transform.position;
     
     // Check collisions above and below
     grounded = false;
     
     for (int i = 0; i<collisionDivisionsX; i ++) {
         float dir = Mathf.Sign(deltaY);
         float x = (p.x + c.x - s.x/2) + s.x/(collisionDivisionsX-1) * i; // Left, centre and then rightmost point of collider
         float y = p.y + c.y + s.y/2 * dir; // Bottom of collider
         
         ray = new Ray(new Vector2(x,y), new Vector2(0,dir));
         Debug.DrawRay(ray.origin,ray.direction);
         
         if (Physics.Raycast(ray,out hit,Mathf.Abs(deltaY) + skin,collisionMask)) {
             // Get Distance between player and ground
             float dst = Vector3.Distance (ray.origin, hit.point);
             
             // Stop player's downwards movement after coming within skin width of a collider
             if (dst > skin) {
                 deltaY = dst * dir - skin * dir;
             }
             else {
                 deltaY = 0;
             }
             
             grounded = true;
             
             break;
             
         }
     }
     
     
     // Check collisions left and right
     movementStopped = false;
     for (int i = 0; i<collisionDivisionsY; i ++) {
         float dir = Mathf.Sign(deltaX);
         float x = p.x + c.x + s.x/2 * dir;
         float y = p.y + c.y - s.y/2 + s.y/(collisionDivisionsY-1) * i;
         
         ray = new Ray(new Vector2(x,y), new Vector2(dir,0));
         Debug.DrawRay(ray.origin,ray.direction);
         
         if (Physics.Raycast(ray,out hit,Mathf.Abs(deltaX) + skin,collisionMask)) {
             // Get Distance between player and ground
             float dst = Vector3.Distance (ray.origin, hit.point);
             
             // Stop player's downwards movement after coming within skin width of a collider
             if (dst > skin) {
                 deltaX = dst * dir - skin * dir;
             }
             else {
                 deltaX = 0;
             }
             
             movementStopped = true;
             break;
             
         }
     }
     
     if (!grounded && !movementStopped) {
         Vector3 playerDir = new Vector3(deltaX,deltaY);
         Vector3 o = new Vector3(p.x + c.x + s.x/2 * Mathf.Sign(deltaX),p.y + c.y + s.y/2 * Mathf.Sign(deltaY));
         ray = new Ray(o,playerDir.normalized);
         
         if (Physics.Raycast(ray,Mathf.Sqrt(deltaX * deltaX + deltaY * deltaY),collisionMask)) {
             grounded = true;
             deltaY = 0;
         }
     }


     Vector2 finalTransform = new Vector2(deltaX,deltaY);
     
     transform.Translate(finalTransform,Space.World);
 }
 
 // Set collider
 public void SetCollider(Vector3 size, Vector3 centre) {
     collider.size = size;
     collider.center = centre;
     
     s = size * colliderScale;
     c = centre * colliderScale;
 }
 
 }