PlayerPrefs.Set<DataType>("hash", value);

If I need to give an example of how it is used, let's examine the code below.

        PlayerPrefs.SetFloat("floatPP", 1.2f); // We created a PlayerPrefs of Float type.
        PlayerPrefs.SetInt("integerPP", 10); // We created a PlayerPrefs of Int type.
        PlayerPrefs.SetString("stringPP", "UrhobA"); // We created a PlayerPrefs of String type.
  

If we wanted to edit these, we would also change the value of the data we want to edit and write it the same way. For example;

        PlayerPrefs.SetFloat("floatPP", 99.99f); // We created a PlayerPrefs of Float type.
        PlayerPrefs.SetInt("integerPP", 99); // We created a PlayerPrefs of Int type.
        PlayerPrefs.SetString("stringPP", "www.urhoba.net"); // We created a PlayerPrefs of String type.
  

Save() Method - Writing PlayerPrefs to Disk

PlayerPrefs.Save();

I think you are wondering why I should use the Save() method, so I will explain right away.

Unity writes the data saved with PlayerPrefs to disk when the "OnApplicationQuit()" function is called; that is, the data is saved to disk just before exiting the game.

In case of exiting the game unexpectedly (crash, phone running out of battery, etc.), the data up to that moment will not be written to disk, so the data will be lost. To prevent this, we use the Save() method.

For an example of its usage, we can use it right below the set methods above.

        
	PlayerPrefs.SetFloat("floatPP", 1.2f); // We created a PlayerPrefs of Float type.
        PlayerPrefs.SetInt("integerPP", 10); // We created a PlayerPrefs of Int type.
        PlayerPrefs.SetString("stringPP", "UrhobA"); // We created a PlayerPrefs of String type.
        PlayerPrefs.Save(); // We wrote the data to disk.
  

Get Methods - Reading PlayerPrefs Data

PlayerPrefs.Get<DataType>("hash");

It is just like using the set method, the only difference is that here we write "Get" instead of "Set," and we don't write anything for the "value" part. Let's see how we use it in code.

        Debug.Log(PlayerPrefs.GetFloat("floatPP").ToString()); // We print a float value to the console.
        Debug.Log(PlayerPrefs.GetInt("integerPP").ToString()); // We print an int value to the console.
        Debug.Log(PlayerPrefs.GetString("stringPP")); // We print a string value to the console.

        float floatValue = PlayerPrefs.GetFloat("floatPP"); // We assign a float value to a float variable.
        int intValue = PlayerPrefs.GetInt("integerPP"); // We assign an int value to an int variable.
        string stringValue = PlayerPrefs.GetString("stringPP"); // We assign a string value to a string variable.
      

Delete Methods - Deleting PlayerPrefs Data

1. DeleteAll();
2. DeleteKey("hash");

PlayerPrefs.DeleteAll();

If we need to examine how it is used in code; 

                
        PlayerPrefs.SetFloat("floatPP", 1.2f);
        PlayerPrefs.SetInt("integerPP", 10);
        PlayerPrefs.SetString("stringPP", "UrhobA");

        PlayerPrefs.DeleteAll(); // All the PlayerPrefs data we created was deleted.
        

DeleteKey("hash") - Deleting a Single PlayerPrefs Data

PlayerPrefs.DeleteKey("hash");

    void Start()
    {
        PlayerPrefsSetBool("boolTest", false); // We save our PlayerPrefs as a bool.
        bool state = PlayerPrefsGetBool("boolTest"); // We retrieve our PlayerPrefs as a bool.
        Debug.Log(state.ToString()); // We print the retrieved data to the console.
    }

    bool PlayerPrefsGetBool(string hash) // We write our function for retrieving the data.
    {
        bool state = (PlayerPrefs.GetInt(hash) == 0) // With a ternary if, we retrieve the integer value, and if the value is 0, we return false; otherwise, not 0, true.
            ? false
            : true;
        return state;
    }

    void PlayerPrefsSetBool(string hash, bool value) // We write our function for saving the data.
    {
        int number = (value == false) // If the incoming data is false, we return 0; otherwise, 1.
            ? 0
            : 1;
        PlayerPrefs.SetInt(hash, number); // We add the numerical value we return as an Int PlayerPrefs.
    }