Reactjs Storing State In Constructor Vs Property

I have a very simple react component that needs to connect to an API and retrieve some JSON data, which will then be used for displaying some information. In the following class/co

Solution 1:

Initializing state in the constructor like your second example is perfectly valid, but your two examples are not the same. You are setting isLoading to true in the class property version, but isLoading to false in the constructor.

If error in null and isLoading is false you will hit the last part of your render method. Since projectInfo is null before your request is complete, you will try to access name on null and get your error.

Set isLoading to true and it should work as expected, or even projectInfo to an empty object {}, but then you will not get the loading indicator.

classMyReportSummaryextendsComponent{
  constructor(props) {
    super(props);

    this.mounted = true;
    this.state = {
      projectInfo: {},
      isLoading: true,
      error: null
    };
  }

  // ...
}