You can do it with `Spread Operator`
<!-- begin snippet: js hide: false console: true babel: false -->
<!-- language: lang-js -->
this.state = {
sundayTime:{
start:"",
end:""
},
mondayTime:{
start:"",
end:""
},
tuesdayTime:{
start:"",
end:""
},
wednesdayTime:{
start:"",
end:""
},
thursdayTime:{
start:"",
end:""
},
fridayTime:{
start:"",
end:""
},
saturdayTime:{
start:"",
end:""
}
};
const sundayTime={...this.state.sundayTime,end:"newEndTime"};
const copy={...state,sundayTime}
console.log(copy)
<!-- language: lang-html -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.6.3/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.6.3/umd/react-dom.production.min.js"></script>
<!-- end snippet -->
React circa 2020
----------------
In the `onClick` callback, call the [state hook's][1] setter function to update the state and re-render:
<!-- begin snippet: js hide: false console: true babel: true -->
<!-- language: lang-js -->
const Search = () => {
const [showResults, setShowResults] = React.useState(false)
const onClick = () => setShowResults(true)
return (
<div>
<input type="submit" value="Search" onClick={onClick} />
{ showResults ? <Results /> : null }
</div>
)
}
const Results = () => (
<div id="results" className="search-results">
Some Results
</div>
)
ReactDOM.render(<Search />, document.querySelector("#container"))
<!-- language: lang-html -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.13.1/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.13.1/umd/react-dom.production.min.js"></script>
<div id="container">
<!-- This element's contents will be replaced with your component. -->
</div>
<!-- end snippet -->
[JSFiddle][2]
React circa 2014
----------------
The key is to update the state of the component in the click handler using `setState`. When the state changes get applied, the `render` method gets called again with the new state:
<!-- begin snippet: js hide: false console: true babel: true -->
<!-- language: lang-js -->
var Search = React.createClass({
getInitialState: function() {
return { showResults: false };
},
onClick: function() {
this.setState({ showResults: true });
},
render: function() {
return (
<div>
<input type="submit" value="Search" onClick={this.onClick} />
{ this.state.showResults ? <Results /> : null }
</div>
);
}
});
var Results = React.createClass({
render: function() {
return (
<div id="results" className="search-results">
Some Results
</div>
);
}
});
ReactDOM.render( <Search /> , document.getElementById('container'));
<!-- language: lang-html -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.6.2/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/15.6.2/react-dom.min.js"></script>
<div id="container">
<!-- This element's contents will be replaced with your component. -->
</div>
<!-- end snippet -->
[JSFiddle][3]
[1]: https://reactjs.org/docs/hooks-state.html
[2]: https://jsfiddle.net/khx30pnv/
[3]: http://jsfiddle.net/kb3gN/15084/
