How could I implement cheat codes in my game?

I would like to implement Doom-style cheat codes. That is when the user types in a given succession of letters, something should happen in my game. How would I go about implementing that?

Its actually pretty straight forward. What you need to consider is the delay before the currently typed in string is cleared, which codes you'll accept and possibly a target GameObject - if you plan on handling the accepted codes somewhere else.

The code below shows a simple implementation. Try saving it out as CheatCodeListener.cs, adding it to a GameObject and populating the codes list with "Test".

using UnityEngine;
using System.Collections;
using System.Collections.Generic;

public class CheatCodeListener : MonoBehaviour
{
    private string m_Keys = "";
    private float m_LastKeyTime;

    public List <string> m_Codes = new List <string> ();
    public float m_ClearDelay = 2.0f;
    public GameObject m_Receiver = null;

    void Start ()
    {
        m_LastKeyTime = Time.time
        for (int i = 0; i < m_Codes.Count; i++)
        {
            m_Codes  <em>= m_Codes *.ToLower ();*</em>
 _*}*_
 _*}*_
 _*void Update ()*_
 _*{*_
 _*if (Input.anyKey)*_
 _*{*_
 <em>*m_LastKeyTime = Time.time;*</em>
 _*}*_
 <em>*else if (Time.time - m_LastKeyTime > m_ClearDelay)*</em>
 _*{*_
 <em>*m_Keys = "";*</em>
 _*}*_
 <em>*m_Keys += Input.inputString.ToLower ();*</em>
 <em>*if (m_Codes.Contains (m_Keys))*</em>
 _*{*_
 <em>*string message = "On" + char.ToUpper (m_Keys [0]) + m_Keys.Substring (1) + "Code";*</em>
 <em>*if (m_Receiver == null)*</em>
 _*{*_
 _*SendMessage (message);*_
 _*}*_
 _*else*_
 _*{*_
 <em>*m_Receiver.SendMessage (message);*</em>
 _*}*_
 <em>*m_Keys = "";*</em>
 _*}*_
 _*}*_
 _*void OnTestCode ()*_
 _*// Handle codes in scripts on the target GameObject (or the current one if*_
 _*// no target is set) by implementing functions named On{Name}Code - note*_
 _*// that the codes are set to be all-lowercase except for the first letter.*_
 _*{*_
 _*Debug.Log ("We caught a code!");*_
 _*}*_
_*}*_
_*```*_

Here : unitynoobs you can download a small project with this answer!