class Foo {

    constructor(name){

      this.name = name

      this.display = this.display.bind(this);

    }

    ...

}

ReactJS is based on...javascript, so the traditional OOP approach to `this` 

is not the same. 

​

When calling functions in class based components as opposed to functional

based components in ReactJS, you lose the `this` context on the object

and instead have it on the function itself.  

​

You counter this behaviour through the useof `.bind()`, by using it

when you call the function, or in the constructor (preferred).