Version: 2017.3
public static int NameToLayer (string layerName);

Description

Given a layer name, returns the layer index as defined by either a Builtin or a User Layer in the Tags and Layers manager.

Returns -1 if not found.

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour { void Example() { Debug.Log(LayerMask.NameToLayer("TransparentFX")); } }