Application.isEditor

static var isEditor : boolean

Description

Are we running inside the Unity editor? (Read Only)

Returns true if the game is being run from the Unity editor; false if run from any deployment target.

JavaScript

if (Application.isEditor) {
    print("We are running this from inside of the editor!");
}

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
    void Example() {
        if (Application.isEditor)
            print("We are running this from inside of the editor!");
        
    }
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

    def Example():
        if Application.isEditor:
            print('We are running this from inside of the editor!')