Storing input Field Values in array not working

Hi Im New to coding i have tried asking a similiar question but it keeps going to page not found, anyway i have a bunch of input fields that i want to store the end edit values in an array, so i can access them easily. but every time i go to store them in the array it dosent work and give a null reference exception.

string dataStore;
public void TitleCollector(string title) //attached to end edit on input box
{
dataStore[0] = title; //
}

before you key-in variable into an array
must declare the array at least once ( at OnEnable() or Start())
dataStore=new string[length you need]