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Bug Is it a bug? PlayerPrefs.GetFloat sometime return default value even though HasKey is true.

Discussion in 'Scripting' started by Bodin, Nov 23, 2022.

  1. Bodin

    Bodin

    Joined:
    Apr 19, 2017
    Posts:
    37
    Hi,

    I'm working on Unity 2021.3.3f1, on Windows standalone platform.

    I got the weird result from PlayerPrefs.GetFloat
    let say I did PlayerPrefs.SetFloat("speed", 1.5f);

    and after the scene start
    if in Start(), I call
    float Speed = PlayerPrefs.GetFloat("speed", 1f);

    the value I got is always 1f.
    (I also checked with PlayerPrefs.HasKey() & use Windows Registry Editor to make sure that the key is there.)

    but if I call it without "default value" overload
    ex. float Speed = PlayerPrefs.GetFloat("speed");
    I got the correct value.

    after Start() has passed, PlayerPrefs.GetFloat("speed", 1f); always return a correct value.

    Is this an intent behavior or bug? anyone experience the same?

    thank in advance for any answer,
    Best regards,
     
  2. Strafe_m

    Strafe_m

    Joined:
    Oct 24, 2022
    Posts:
    72
    I wasn't able to reproduce the issue, works fine for me, do you mind showing how you exactly set and get the float in your code
     
  3. Kurt-Dekker

    Kurt-Dekker

    Joined:
    Mar 16, 2013
    Posts:
    38,689
    I'm guessing you simply have a bug in your logic. Here's how to track it down:

    You must find a way to get the information you need in order to reason about what the problem is.

    Once you understand what the problem is, you may begin to reason about a solution to the problem.

    What is often happening in these cases is one of the following:

    - the code you think is executing is not actually executing at all
    - the code is executing far EARLIER or LATER than you think
    - the code is executing far LESS OFTEN than you think
    - the code is executing far MORE OFTEN than you think
    - the code is executing on another GameObject than you think it is
    - you're getting an error or warning and you haven't noticed it in the console window

    To help gain more insight into your problem, I recommend liberally sprinkling
    Debug.Log()
    statements through your code to display information in realtime.

    Doing this should help you answer these types of questions:

    - is this code even running? which parts are running? how often does it run? what order does it run in?
    - what are the values of the variables involved? Are they initialized? Are the values reasonable?
    - are you meeting ALL the requirements to receive callbacks such as triggers / colliders (review the documentation)

    Knowing this information will help you reason about the behavior you are seeing.

    You can also supply a second argument to Debug.Log() and when you click the message, it will highlight the object in scene, such as
    Debug.Log("Problem!",this);


    If your problem would benefit from in-scene or in-game visualization, Debug.DrawRay() or Debug.DrawLine() can help you visualize things like rays (used in raycasting) or distances.

    You can also call Debug.Break() to pause the Editor when certain interesting pieces of code run, and then study the scene manually, looking for all the parts, where they are, what scripts are on them, etc.

    You can also call GameObject.CreatePrimitive() to emplace debug-marker-ish objects in the scene at runtime.

    You could also just display various important quantities in UI Text elements to watch them change as you play the game.

    If you are running a mobile device you can also view the console output. Google for how on your particular mobile target, such as this answer or iOS: https://forum.unity.com/threads/how-to-capturing-device-logs-on-ios.529920/ or this answer for Android: https://forum.unity.com/threads/how-to-capturing-device-logs-on-android.528680/

    Another useful approach is to temporarily strip out everything besides what is necessary to prove your issue. This can simplify and isolate compounding effects of other items in your scene or prefab.

    Here's an example of putting in a laser-focused Debug.Log() and how that can save you a TON of time wallowing around speculating what might be going wrong:

    https://forum.unity.com/threads/coroutine-missing-hint-and-error.1103197/#post-7100494

    When in doubt, print it out!(tm)

    Note: the
    print()
    function is an alias for Debug.Log() provided by the MonoBehaviour class.

    Here's an example of simple persistent loading/saving values using PlayerPrefs:

    https://gist.github.com/kurtdekker/01da815d2dfd336a925ae38019c3a163

    Useful for a relatively small number of simple values.