How do I make a loop to pull keys/values from local storage and assign them to instance variables ?

I have been trying to do this with different ways with no success.

I want to create a "Level progress " layout for the game, with the number of stars player received next to each completed level.(see image)

When the player complete a level, he will receive stars. This data will be saved in local storage in below format

key - Value

level number - number of stars received

When player go to "Level progress" all the completed levels will be shown with number of stars as a sprite next to it.

for this I need to pull data from local storage and assign the value to a instance variable of corresponding sprite.

How do I do this ?