react child to parent code example

Example 1: pass data from child component to parent component react native

class Parent extends React.Component {
  state = { message: "" }
  callbackFunction = (childData) => {
        this.setState({message: childData})
  },
  render() {
          return (
              <div>
                   <Child1 parentCallback = {this.callbackFunction}/>
                   <p> {this.state.message} </p>
              </div>
          );
  }
}

class Child1 extends React.Component{
  sendData = () => {
           this.props.parentCallback("Hey Popsie, How’s it going?");
      },
  render() { 
  //you can call function sendData whenever you'd like to send data from child component to Parent component.
      }
};

Example 2: communication child to parent react js

import React from 'react';

import Child from './Child'

export default class Parent extends React.Component {

      constructor(props){

            super(props);

            this.state ={ text:''};

       }

     handleChangeInParent = (event) => {

             this.setState({text:event.target.value})

     }

    render() {

        return (

                  <>

                     <p>You have written: </p>

                     <p>{this.state.text}</p>

                     <Child handleChange={this.handleChangeInParent}/>

                   </>

                )

      }

}

Example 3: pass element from child to parent react

Parent:

<div className="col-sm-9">
     <SelectLanguage onSelectLanguage={this.handleLanguage} /> 
</div>

Child:

handleLangChange = () => {
    var lang = this.dropdown.value;
    this.props.onSelectLanguage(lang);            
}