React native interview questions

 Q.1 Can we share state between components ?

Answer: We can't send state between components. But props do. We can send props between components.

Q.2 Can we make SectionList with the help of custom map() or flat-list ?

Answer: Yes / But SectionList provide many extra usefull features by-default. So we should use SectionList.

Q.3 Why we use  render() method /

Answer: In classes, when we need to return/print data/UI/View then we need that function to display.

Q.4 How we define state in class component ?

Answer: We need contructor method. It is a life-cycle method hook call/run automatically. In constructor we define keyword "this.state = {}". This is an object.

Note: Every ley in state object is a state.

constructor() {

    this.state = {

        name : 'Adnan' ,

        country: 'Pakistan'   

    }

}

this.state came from parent class conponent. To use parent class we use the super() method in contsructor.

It also same in Java,Typescript.

Display state like so { this.state.name }