/Javascript/React/React how to update state array

React how to update state array

How to add array data on state react

this.setState({ myArray: [...this.state.myArray, 'new value'] }) //simple value
this.setState({ myArray: [...this.state.myArray, ...[1,2,3] ] }) //another array

Source: stackoverflow.com

React how to update state array

const initialState = [
    { name: "foo", counter: 0 },
    { name: "far", counter: 0 },
    { name: "faz", counter: 0 }
  ];

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

const clickButton = () => {
	// 1. Make a shallow copy of the array
	let temp_state = [...state];
	
	// 2. Make a shallow copy of the element you want to mutate
	let temp_element = { ...temp_state[0] };
	
	// 3. Update the property you're interested in
	temp_element.counter = temp_element.counter+1;
	
	// 4. Put it back into our array. N.B. we *are* mutating the array here, but that's why we made a copy first
	temp_state[0] = temp_element;
	
	// 5. Set the state to our new copy
	setState( temp_state );
}

Source: stackoverflow.com

React native update state array of objects

let markers = [ ...this.state.markers ];
markers[index] = {...markers[index], key: value};
this.setState({ markers });

Source: stackoverflow.com

React native update state array of objects

let newMarkers = markers.map(el => (
      el.name==='name'? {...el, key: value}: el
))
this.setState({ markers });

Source: stackoverflow.com

Similar codes

0 vote358 views1 answer
React big calendar messages
Javascript React
0 vote335 views2 answers
React composition
Javascript React
133 votes606 views5 answers
Npx create-react-app
Javascript React
3 votes326 views3 answers
React Components
Javascript React
0 vote353 views1 answer
Close button react
Javascript React
13 votes376 views4 answers
Passing data in react router history,push
Javascript React
2 votes377 views2 answers
React native image swiper
Javascript React
1 vote318 views1 answer
Network request failed fetch react native
Javascript React
0 vote378 views1 answer
Truncate function react
Javascript React
0 vote373 views1 answer
React-drag-drop-files open twice
Javascript React