how to pass props to child in react code example

Example 1: pass state to child react

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

Example 2: react pass props to children

import React, { Children, isValidElement, cloneElement } from 'react';

const Child = ({ doSomething, value }) => (
  <div onClick={() => doSomething(value)}>Click Me</div>
);

function Parent({ children }) {
  function doSomething(value) {
    console.log('doSomething called by child with value:', value);
  }

  render() {
    const childrenWithProps = Children.map(children, child => {
      // Checking isValidElement is the safe way and avoids a TS error too.
      if (isValidElement(child)) {
        return cloneElement(child, { doSomething })
      }

      return child;
    });

    return <div>{childrenWithProps}</div>
  }
};

ReactDOM.render(
  <Parent>
    <Child value="1" />
    <Child value="2" />
  </Parent>,
  document.getElementById('container')
);

Example 3: pass props in react

/* PASSING THE PROPS to the 'Greeting' component */
const expression = 'Happy';
<Greeting statement='Hello' expression={expression}/> // 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 <h1>{this.props.statement} I am feeling {this.props.expression} today!</h1>;
  }
}