Successional key pressed detection

Problem to be solved :

Need to detect whether the player has pressed the specified key successionally to invoke 'running' animation.

Solution :

Record the time when the first and second time the key is pressed.
Check if their difference (in absolute) is smaller than 0.5

    // successional key pressed detection viriable
    float FirstPressTime = -100; // time for first press key
    float SecondPressTime = 100; // time for second press key
    private bool FirstPress = false; // bool variable used for successional key pressed detection

    void WalkAndRun()
    {
        if (Input.GetKeyDown(KeyCode.RightArrow))
        {
            bool onechance = false; // only one chance for each press, in case it records both first and second press


            StartWalking(); // start walking on key down

            if (FirstPress == false) // 
            {
                FirstPressTime = Time.time;
                FirstPress = true;
                onechance = true;

                Debug.Log("FP" + FirstPressTime);
            }

            if (FirstPress == true && onechance == false) { 
                SecondPressTime = Time.time;
                FirstPress = false;

                Debug.Log("SP" + SecondPressTime);
            }
            if (Mathf.Abs(SecondPressTime - FirstPressTime) < 0.5f)
                StartRunning();
            else
            { }
        }
        
        if (Input.GetKeyUp(KeyCode.RightArrow))
        {
            StopWalking();
            StopRunning();
        }
    }