setting state in function react native code example

Example 1: use propTypes in react function

import React from 'react';
import { PropTypes } from 'prop-types';

const student = (props) => {
  return (
    <div>
      <p>Student Name: {props.name}</p>
      <p>Age: {props.age}</p>
    </div>
  );
};

student.propTypes = {
  name: PropTypes.string,
  age: PropTypes.number
};

export default student;

Example 2: state with react functions

import React, { useState } from 'react';

function Example() {
  // Declare a new state variable, which we'll call "count"
  const [count, setCount] = useState(0);

  return (
    <div>
      <p>You clicked {count} times</p>
      <button onClick={() => setCount(count + 1)}>
        Click me
      </button>
    </div>
  );
}

Example 3: prevstate in react

handleClick() {
        this.setState(prevState => {
            return {
                count: prevState.count + 1
            }
        })
    }