react pass var to parent code example

Example 1: react pass prop to parent

//Form (Parent)
import React, { useState, Component } from 'react';
import Input from '../../shared/input-box/InputBox'

const Form = function (props) {

    const [value, setValue] = useState('');

    const onchange = (data) => {
        setValue(data)
        console.log("Form>", data);
    }

    return (
        <div>
            <Input data={value} onchange={(e) => { onchange(e) }}/>
        </div>
    );
}
export default Form;

//Input Box (Child)
import React from 'react';

const Input = function (props) {
    console.log("Props in Input :", props);

    const handleChange = event => {
        props.onchange(event.target.value);
    }

    return (
        <div>
            <input placeholder="name"
                id="name"
                onChange= {handleChange}
            />
        </div>
    );
}
export default Input;

Example 2: how to pass state from parent to child in react

class SomeParentComponent extends React.Component {
  constructor(props) {
    super(props);
    this.state = {color: 'red'};
  }
  render() {
    return <SomeChildComponent color={this.state.color} />;
  }
}