/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

4 votes272 views4 answers
React native android safeareaview
Javascript React
16 votes320 views3 answers
Start react native
Javascript React
56 votes273 views6 answers
Useref react
Javascript React
4 votes308 views2 answers
HandleClick react
Javascript React
2 votes306 views1 answer
React native image source local file
Javascript React
0 vote312 views1 answer
News api react native
Javascript React
-1 vote314 views1 answer
React check if browser is in dark mode
Javascript React
14 votes298 views2 answers
Border react native
Javascript React
0 vote322 views1 answer
How to update the react version in next js app
Javascript React
0 vote293 views1 answer
How to align text vertically center beside an image in react native
Javascript React