How to use handle change event on text box to update react?

Question

Below is the code, where on preload all items get bind inside the text box, and with the help of the same text box, I want to update the value of state in react. items state get's updated but it throws an error as soon as the handlechange method execution gets over. items.map is not a function. How can I use handle change function on the text box to update the array state?

Please check the attachment in which I have attached the text file.