/Javascript/React/How to update react state array

How to update react state array

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

How to update react state array

const [array, setArray] = useState([1, 2, 3])

// Add
setArray(prevArray => [...prevArray, 4]); // -> [1, 2, 3, 4]

// Remove last entry
setArray(prevArray => prevArray.splice(0, prevArray.length - 1)); // -> [1, 2, 3]

Similar codes

1 vote180 views1 answer
How to change the tab text in React
Javascript React
1 vote180 views1 answer
On_raw_reaction_add example
Javascript React
0 vote203 views1 answer
How to add icon in react js
Javascript React
1 vote214 views4 answers
Notification react native
Javascript React
0 vote200 views1 answer
How To Set Opacity of a View In React Native
Javascript React
9 votes185 views2 answers
React select options
Javascript React
8 votes203 views2 answers
Set value as object in react hooks
Javascript React
0 vote206 views1 answer
React native text area form
Javascript React
0 vote235 views1 answer
React-leaflet/core/cjs/pane.js:7%20error15-Jun-2021%2000:45:06%20%20%20%20%20%20const%20pane%20=%20props.pane%20??%20context.pane;
Javascript React
0 vote171 views1 answer
HandleClickoutside custom hook react
Javascript React