React change UseState from Child Component

user_11412183 0
Viewed 707

Is it possible to change the value from a useState from inside the child component?

Parent:

const [state, setState] = useState(false);

return <Child func={() => setState(true)}/>

Child:

return <Button onClick={props.func}> Click me to set the state </Button>

It doesn't work this way, is there any way it could work? Thank you

react-component react-hooks reactjs javascript
3 Answers

You can do something like this

//PARENT
export default function Parent({}) {
  const [state, setState] = useState(false);
        function setParentValue(value){
             setState(value)
       }

        return <Child setValue={setParentValue} />

}

//CHILD
export default function Child({setValue}) {
  function buttonHandler(){
      setValue('value')
 }
  return <Button onClick={buttonHandler}> Click me to set the state </Button>

}
user_91615490

That should work, as long as you also provide a way to look at the changed stateful value:

const { useState } = React;
const App = () => {
  const [state, setState] = useState(false);
  return (
    <div>
      State: {String(state)}
      <Child func={() => setState(true)}/>
    </div>
  );
};
const Child = (props) => {
  return <button onClick={props.func}> Click me to set the state </button>;
};

ReactDOM.render(<App />, document.querySelector('.react'));
<script crossorigin src="https://unpkg.com/react@16/umd/react.development.js"></script>
<script crossorigin src="https://unpkg.com/react-dom@16/umd/react-dom.development.js"></script>
<div class='react'></div>

user_95152070

What you have looks OK. But do you have a <Button> component? If not, lowercase the "b" and use html's <button>.

const Parent = () => {
  const [state, setState] = React.useState(false);
  
  const toggleState = () => setState(prevState => !prevState)
  
  return (
    <div>
      <p>Parent State: {String(state)}</p>
      <Child toggleState={toggleState}/>
    </div>
  );
};

const Child = ({toggleState}) => {
  return <button onClick={toggleState}>Child Button</button>;
};



ReactDOM.render(<Parent />, document.getElementById("root"));
<script crossorigin src="https://unpkg.com/react@16/umd/react.development.js"></script>
<script crossorigin src="https://unpkg.com/react-dom@16/umd/react-dom.development.js"></script>
<div id="root"></div>

user_76690100
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