Constructor is no more | React

Yes, you read it right! There is no more constructor in class component in react.js. You must have seen the traditional react code similar to below

class App extends Component {
  constructor(props) {
    super(props);

    this.state = {
      toggle: true,
    };
  }
}

as per new react(v0.13.0-beta), this can be written in a new format

class App extends Component {
    state = {
      toggle: true,
    };
}

This was inspired by TypeScript’s property initializers.

Advantages:

• Much cleaner way to write

References

• https://reactjs.org/blog/2015/01/27/react-v0.13.0-beta-1.html#es7-property-initializers
• https://github.com/tc39/proposal-class-fields

Comments

[Asif Vora]

So, how can we set props value in default state.

[Ashish Singh Rawat]

class yourComponent extends React.Component {
state = {
x: this.props.initialX,
// You can even call functions and class methods:
y: this.someMethod(this.props.initialY),
};
}