Trying to write a function that checks if 2 keys are pressed

Question

So I'm trying to write a function that checks if 2 keys are pressed within 1 second if each other:

 bool IfTwoKeysPressed(string Key1, string Key2)
 {
     float FirstKeyPress = 20;
     float SecondKeyPress = 50;
     float TimePressedDelay = 1;
     bool KeysPressed = false;

     if (Input.GetKeyDown(Key1))
     {
         FirstKeyPress = Time.time;
     }
     if (Input.GetKeyDown(Key2))
     {
         SecondKeyPress = Time.time;
     }
     if (Mathf.Abs(SecondKeyPress - FirstKeyPress) <= TimePressedDelay)
     {
         FirstKeyPress = 20;
         SecondKeyPress = 50;
         KeysPressed = true;
     }
     Debug.Log(KeysPressed);
     return KeysPressed;
 }

Problem is when I call this function in Update(), checking the delay between the 2 presses doesn't work since the function happens within 1 frame and resets. Transferring the code into Update() works but in my game I'm going to have to check a lot of key combinations and would prefer not having to creating all the variables and writing this code every time.

Answer 1

You have to store the last times the keys have been pressed manually. Then, each time a new key has been pressed, check if all the keys have been presses in your time frame (1 second). Let me give you a helper class that manages that:

 using System;
 using System.Collections.Generic;
 using UnityEngine;
 
 [Serializable]
 public class MultiKeyPressChecker
 {
     [Serializable]
     private class KeyData
     {
         [SerializeField, Tooltip("key that has to be pressed to trigger")] private KeyCode key = KeyCode.A;
 
         [SerializeField]private float lastPressTime = float.NegativeInfinity;
 
         public void Update()
         {
             if (Input.GetKeyDown(key))
             {
                 lastPressTime = Time.time;
             }
         }
 
         public bool GetWasPressed(float timeFrame)
         {
             return Time.time - timeFrame < lastPressTime;
         }
 
         public void ClearLastKeyPressTime()
         {
             lastPressTime = float.NegativeInfinity;
         }
     }
 
 
     [SerializeField, Tooltip("keys that have to be pressed in the timeframe to make the check trigger")]
     private List<KeyData> keys;
 
     [SerializeField, Tooltip("duration in which all specified keys have to be pressed")]
     private float timeFrame = 1f;
 
     public bool Check()
     {
         foreach (KeyData key in keys)
         {
             //update last press times of keys
             key.Update();
         }
 
         foreach (KeyData key in keys)
         {
             //if any of the keys was not pressed in the timeframe, return false
             if (!key.GetWasPressed(timeFrame))
             {
                 return false;
             }
         }
 
         //else clear last key presses and return true (all keys have been pressed in the timeframe)
         foreach (KeyData key in keys)
         {
             key.ClearLastKeyPressTime();
         }
         return true;
     }
 }

You can use this helper class like in this example script:

 using UnityEngine;
 
 public class MultiKeyPressExample : MonoBehaviour
 {
     [SerializeField] private MultiKeyPressChecker keyPressChecker;
 
     private void Update()
     {
         if (keyPressChecker.Check())
         {
             Debug.Log("all the specified keys have been pressed in the timeframe");
         }
     }
 }

Just assign the keys you are interested in and the allowed timeframe in the inspector and you are good to go.

Answer 2

I created a double key press script. Thus, if other scripts need to use it, just add it and check for the keys you need. I also changed a few lines of code as well, as I don't think you need to keep time for each button press.

 using UnityEngine;
 
 // I wouldn't worry about time for each key.  You just need a global time from the last one clicked
 public class DoubleKeyPress : MonoBehaviour
 {
     bool key1Pressed;
     bool key2Pressed;
     float countDownSinceKeyPressed = 0;
     float TimePressedDelay = 1;
 
 
     public bool IfTwoKeysPressed(KeyCode key1, KeyCode key2)
     {
         countDownSinceKeyPressed -= Time.deltaTime;
         if (countDownSinceKeyPressed <= 0)
         {
             key1Pressed = false;
             key2Pressed = false;
         }
 
         if (Input.GetKeyDown(key1))
         {
             countDownSinceKeyPressed = TimePressedDelay;
             key1Pressed = true;
         }
 
         if (Input.GetKeyDown(key2))
         {
             countDownSinceKeyPressed = TimePressedDelay;
             key2Pressed = true;
         }
 
         if (key1Pressed && key2Pressed) countDownSinceKeyPressed = 0f;
 
         return key1Pressed && key2Pressed;
     }
 }

Here is a random script that adds it and uses it.

 using UnityEngine;
 
 public class UseDoubleKeyPress : MonoBehaviour
 {
     DoubleKeyPress keyPress;
 
 
     void Awake ()
     {
         keyPress = gameObject.AddComponent<DoubleKeyPress>();
     }
     
 
     void Update ()
     {
         if (keyPress.IfTwoKeysPressed(KeyCode.A, KeyCode.B))
         {
             Debug.LogError("Buttons Pressed");
         }
     }
 }

Trying to write a function that checks if 2 keys are pressed

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