react pass function as prop code example

Example 1: defining functions in react

export default class Archive extends React.Component { 

    saySomething(something) {
        console.log(something);
    }

    handleClick(e) {
        this.saySomething("element clicked");
    }

    componentDidMount() {
        this.saySomething("component did mount");
    }

    render() {
        return ;
    }
}

Example 2: pass props in react

/* PASSING THE PROPS to the 'Greeting' component */
const expression = 'Happy';
 // statement and expression are the props (ie. arguments) we are passing to Greeting component

/* USING THE PROPS in the child component */
class Greeting extends Component {
  render() {
    return 
{this.props.statement} I am feeling {this.props.expression} today!
;
  }
}

Example 3: pass function with parameter as prop

class SomeComponent extends Component{

    constructor(props){
        super(props);
        //does whatever stuff        
        this.myFunction = this.myFunction.bind(this);

    }

    //(only applicable to raw and normal forms)
    myFunction(param){
        console.log('do something: ', param);
    }

    render(){
     return (
)
    }
}

class ChildComponent1{
      render(){
  return (
)
    }
}

class ChildComponent2{
      render(){
  return (this.props.myFunction(param)}>SomeButton)
    }
}

Example 4: react native function

class Foo extends Component {
  handleClick() {
    console.log('Click happened');
  }
  render() {
    return Click Me;
  }
}

Example 5: pass params react js

//pass color from parent -> child

App.js -> ColorPicker (Components/ColorPicker.js)

/// parent App.js
import ColorPicker from './Component/ColorPicker';

class App extends Component {
  
   constructor(props) {
        super(props);
        this.state = {
            color:  'red',
        };
    }
  
   render() {
        return (
			

    			     
			
		)
    }
}export default App;        

/// child ColorPicker
import React, { PureComponent } from 'react';

class ColorPicker extends PureComponent {  

    constructor(props) {
        super(props);
        this.state = {
            colors: ['red', 'green', 'blue', 'yellow', 'purple'],
        };
    }

    render() {

        var elementColors = this.state.colors.map((c, index) => {
            return 
                   
        });
}
export default ColorPicker;    

// ---------------------------------------

//pass params from child -> parent
// onClick => setActiveColor -> this.props.onReceiverColor(c);
ColorPicker (Components/ColorPicker.js) -> App.js 

/// child ColorPicker
import React, { PureComponent } from 'react';

class ColorPicker extends PureComponent {  

    constructor(props) {
        super(props);
        this.state = {
            colors: ['red', 'green', 'blue', 'yellow', 'purple'],
        };
    }
  
    setActiveColor = (c)  => {
        this.props.onReceiverColor(c);
    }

    render() {

        var elementColors = this.state.colors.map((c, index) => {
            return  this.setActiveColor(c) }  // click into color c will pass params c to Bai11Practice.js
                        >
                   
        });
}
export default ColorPicker;        

// Parent
import React, { Component } from 'react';
import ColorPicker from './Component/ColorPicker';

class App extends Component {

    onSetColor(c) {
        alert(c);
    }

    render() {
        return (
		             
        );
    }
}export default App;