Converting My JS code into UnityScript

So I recently learnt JavaScript at a beginner level but was able to make some basic things like a fruit machine, dice game and a simple dodging game. But I am trying to figure out the main difference between UnityScript and JavaScript and to do this I thought I would try to import my code and alter it to work with unity.

So this is my issue I created a simple thing to suggest the characters position and alter it when the user presses the left or right key (I am aware many of it is probably wrong but I am learning), however Unity passes some errors which makes me wonder.

The Errors I have received that baffle me are:

• PlayerController.js(9,26): BCE0044: expecting ), found '='.

• PlayerController.js(9,27): BCE0043: Unexpected token: >.

So to summarise I am asking if this is wrong why? and does this mean Unity does not accept a simple => to check that a variable is equal to or greater than a value/function and if that is the case what should I use instead.

Thank for any help the code is below.

 var posX = 0;
 var maxLeft = -10;
 var maxRight = 10;
 
 function Update()
 {
     if (Input.GetButton("left")) 
     {
         if (posX => maxLeft)
         {
             //If the position is equal to maxLeft then it will not do anything.
         }
         else
         {
             //Move character left on screen;
             posX = posX-0.5;
             transform.position = (0, posX, 0);
         }  
     }
     else if (Input.GetButton("right"))
     {
         if (posX => maxRight)
         {
             //If the position is equal to maxRight then it will not do anything.
         }
         else
         {
             //move character right on screen;
             posX = posX+0.5;
             transform.position = (0, posX, 0);
         }
     }
     else
     {
     //Left or Right arrow key not pressed so do nothing.
     }
 }