C# to Java Script

Hello guys!
i really, really would like someone help me convert this to java script:

using UnityEngine;
using System.Collections;
public class PlayerController : MonoBehaviour {
  public float walkSpeed = 1; // player left right walk speed
  private bool _isGrounded = true; // is player on the ground?
  Animator animator;
  //some flags to check when certain animations are playing
  bool _isPlaying_crouch = false;
  bool _isPlaying_walk = false;
  bool _isPlaying_hadooken = false;
  //animation states - the values in the animator conditions
  const int STATE_IDLE = 0;
  const int STATE_WALK = 1;
  const int STATE_CROUCH = 2;
  const int STATE_JUMP = 3;
  const int STATE_HADOOKEN = 4;
  string _currentDirection = "left";
  int _currentAnimationState = STATE_IDLE;
  // Use this for initialization
  void Start()
  {
  //define the animator attached to the player
  animator = this.GetComponent<Animator>();
  }
  // FixedUpdate is used insead of Update to better handle the physics based jump
  void FixedUpdate()
  {
  //Check for keyboard input
  if (Input.GetKeyDown (KeyCode.Space))
  {
  changeState (STATE_HADOOKEN);
  }
  else if (Input.GetKey ("up") && !_isPlaying_hadooken && !_isPlaying_crouch)
  {
  if(_isGrounded)
  {
  _isGrounded = false;
  //simple jump code using unity physics
  rigidbody2D.AddForce(new Vector2(0, 250));
  changeState(STATE_JUMP);
  }
  }
  else if (Input.GetKey ("down"))
  {
  changeState(STATE_CROUCH);
  }
  else if (Input.GetKey ("right") && !_isPlaying_hadooken )
  {
  changeDirection ("right");
  transform.Translate(Vector3.left * walkSpeed * Time.deltaTime);
  if(_isGrounded)
  changeState(STATE_WALK);
  }
  else if (Input.GetKey ("left") && !_isPlaying_hadooken)
  {
  changeDirection ("left");
  transform.Translate(Vector3.left * walkSpeed * Time.deltaTime);
  if(_isGrounded)
  changeState(STATE_WALK);
  }
  else
  {
  if(_isGrounded)
  changeState(STATE_IDLE);
  }
  //check if crouch animation is playing
  if (animator.GetCurrentAnimatorStateInfo(0).IsName("ken_crouch"))
  _isPlaying_crouch = true;
  else
  _isPlaying_crouch = false;
  //check if hadooken animation is playing
  if (animator.GetCurrentAnimatorStateInfo(0).IsName("ken_hadooken"))
  _isPlaying_hadooken = true;
  else
  _isPlaying_hadooken = false;
  //check if strafe animation is playing
  if (animator.GetCurrentAnimatorStateInfo(0).IsName("ken_walk"))
  _isPlaying_walk = true;
  else
  _isPlaying_walk = false;
  }
  //--------------------------------------
  // Change the players animation state
  //--------------------------------------
  void changeState(int state){
  if (_currentAnimationState == state)
  return;
  switch (state) {
  case STATE_WALK:
  animator.SetInteger ("state", STATE_WALK);
  break;
  case STATE_CROUCH:
  animator.SetInteger ("state", STATE_CROUCH);
  break;
  case STATE_JUMP:
  animator.SetInteger ("state", STATE_JUMP);
  break;
  case STATE_IDLE:
  animator.SetInteger ("state", STATE_IDLE);
  break;
  case STATE_HADOOKEN:
  animator.SetInteger ("state", STATE_HADOOKEN);
  break;
  }
  _currentAnimationState = state;
  }
  //--------------------------------------
  // Check if player has collided with the floor
  //--------------------------------------
  void OnCollisionEnter2D(Collision2D coll)
  {
  if (coll.gameObject.name == "Floor")
  {
  _isGrounded = true;
  changeState(STATE_IDLE);
  }
  }
  //--------------------------------------
  // Flip player sprite for left/right walking
  //--------------------------------------
  void changeDirection(string direction)
  {
  if (_currentDirection != direction)
  {
  if (direction == "right")
  {
  transform.Rotate (0, 180, 0);
  _currentDirection = "right";
  }
  else if (direction == "left")
  {
  transform.Rotate (0, -180, 0);
  _currentDirection = "left";
  }
  }
  }
}

Here the origin post :Creating 2D animation states in Unity3D : Part 3 – Switching animations with keyboard input – John Stejskal : Software and Game Developer

  1. Please use CODE tags when posting source code.
  2. What part of the script do you need assistance with?

actually i dont know nothing about this code.