Salar Gholizadeh

The :number part of the path /roster/:number means that the part of the pathname that comes after /roster/ will be captured and stored as match.params.number. For example, the pathname /roster/6 will generate a params object :

The element rendered by the <Route> will be passed a number of props. These will be the match object, the current location object [6], and the history object (the one created by our router) [7].