Making a List for Inventory System, Got an error in finding constructors and variables

Hello everyone, I am currently following tutorials on making an Inventory system for my game. Right now I have a code for my Item (IS_ItemHandler) and an Inventory Management code (IS_Items).
I made a public class in ItemHandler with variables and an itemsList in Items calling those variables.

I have copied the tutorials exactly, but it is 2 years old. So did a Unity update cause this error? I am teaching myself Javascript and still heavily an amateur. Sorry if my coding vocab is off.

I am getting this error: Assets/My Assets/Javascript/IS_Items.js(19,34): BCE0024: The type ‘ItemHandler’ does not have a visible constructor that matches the argument list ‘(int, UnityEngine.Texture2D, String, String, boolean, ItemType, Rarity)’.

Let me know if you need for details. Thank you!

Here are both of my codes:

IS_ItemHandler -

public class ItemHandler
{
var itemID : int;
var icon : Texture2D;
var name : String;
var description : String;
var equipped : boolean = false;
var itemType : ItemType;
var rare : Rarity;
}

function ItemHandler(ID : int, ItemIcon : Texture2D, ItemName : String, ItemDescription : String, Equipped : boolean, Type : ItemType, Rareness : Rarity)
{
this.itemID = ID;
this.icon = ItemIcon;
this.name = ItemName;
this.description = ItemDescription;
this.equipped = Equipped;
this.itemType = Type;
this.rare = Rareness;
}


enum ItemType
{
	Battery,
	Health,
	Door,
	Leftarm,
	Rightarm,
	Leftleg,
	Rightleg,
	Brain,
	TwoHands,
	OneHand
};

enum Rarity
{
	Verycommon,
	common,
	uncommon,
	lore,
	rare,
	veryrare,
	extremerare,
	prime
};

IS_Items

import System.Collections.Generic;
var itemsList : List.<ItemHandler> = new List.<ItemHandler>();

private var item1Icon : Texture2D;
private var item2Icon : Texture2D;
private var item3Icon : Texture2D;

function Start () 
{	
	//Icons Items Start
	item1Icon = Resources.Load("Items/Item1", Texture2D);
	item2Icon = Resources.Load("Items/Item2", Texture2D);
	item3Icon = Resources.Load("Items/Item3", Texture2D);
	//Icons Items End

	//Items Start
	//ID int, Icon Texture, Name String, Desc. String, Equip Boolean, Type ItemType, rarityList Rarity
	//0
	itemsList.Add(ItemHandler(1, item1Icon, "Battery", "Battery's Mock Description.", false, ItemType.Battery, Rarity.Verycommon));
}

Try putting the function ItemHandler (…){…} inside of the ItemHandler class like so:

public class ItemHandler
     {
     var itemID : int;
     var icon : Texture2D;
     var name : String;
     var description : String;
     var equipped : boolean = false;
     var itemType : ItemType;
     var rare : Rarity;

function ItemHandler(ID : int, ItemIcon : Texture2D, ItemName : String,      ItemDescription : String, Equipped : boolean, Type : ItemType, Rareness : Rarity)
     {
     this.itemID = ID;
     this.icon = ItemIcon;
     this.name = ItemName;
     this.description = ItemDescription;
     this.equipped = Equipped;
     this.itemType = Type;
     this.rare = Rareness;
     }
}

I’m not 100% sure if this will fix it, as I haven’t programmed with JS in Unity for a while. I know for C# though, it must be inside of the actual class.