Question

What is ithe main purpose of constructor in React JS?

Answer 1

The constructor is mainly used for two purposes,

1. To initialize local state by assigning object to this.state
2. For binding event handler methods to the instance For example, the below code covers both the above cases,

constructor(props) {
  super(props);
  // Don't call this.setState() here!
  this.state = { counter: 0 };
  this.handleClick = this.handleClick.bind(this);
}