Check if pressed key exists inside an array of KeyCodes

Is there anything like this for KeyCode?

 using UnityEngine;

 void LateUpdate ()
 {
      KeyCode[] keyCheck = new KeyCode[4];
      if (Input.anyKeyDown == keyCheck[2])
           Debug.Log(Input.inputString);
 }

You may be looking for something like this. Please be sure to change the declaration (the first line) to the Start function!

    void Update()
    {
        KeyCode[] keycodes = new KeyCode[]{ KeyCode.W, KeyCode.A, KeyCode.S, KeyCode.D };
        for (int i = 0; i < keycodes.Length; i++) if (Input.GetKeyDown(keycodes_)) Debug.Log("Pressed " + keycodes*);*_

}

Right now you are creating an array of KeyCode types. Which has been initialised but not populated.
If I understand what you are trying to do i think you’d need to do this

   KeyCode[] keyCodes = new KeyCode[]
    {
        KeyCode.A,
        KeyCode.B
    };

    if (Input.GetKeyDown(keyCodes[2]))
    {
        Debug.Log(Input.inputString);
    }