MutableLiveData doesn't apply change

    private var number = MutableLiveData(0)

    fun addOne(){
          number.value?.let { it + 1 }
    }
    

I would like to increase my mutableLiveData by 1 all the time using my function.
But it still shows 0. What could be wrong there ?

>Solution :

you are not change live data value …you are just get the value :
you should

number.value = number.value!! + 1