Version: 2018.1
public static bool isPlaying ;

Description

Returns true when called in any kind of built Player, or when called in the Editor in Play Mode (Read Only).

In a built Player, this method will always return true.

In the Editor, it will return true if the Editor is in Play Mode.

See Also: Application.Application, ExecuteAlways.

using UnityEngine;

class Example : MonoBehaviour { void Start() { if (Application.isPlaying) { print("In player or playmode"); } } }