I am trying to build a todo list app with React. Getting the error “Cannot read property of handleChange undefined”. Below is the code i am working on. Moreover, todosData is an array of objects having id, text and completed(boolean – true/false) as properties. The content.js is as follows, And finally the array todosData, Answer Because this is function-scoped, except for arrow-functions. Alternative, if you have to use function. See also How to access the correct `this` inside a callback?