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VisualizaçõesHow to destructure an Object from Array with useState in React
I need to destructure the filter Object from Array with useState in React, but I can't get it.
const [filter, setFilter] = useState([]);
const { column, comparison, value } = filter;
console.log(column); // undefined
I tried braces, brackets, and still getting undefined. Does anyone knows how to get that values?
The filter object:
filter: [
{
column: 'population',
comparison: 'greater than',
value: '100000',
}
]
Console log:
3 Respostas
Responde à pergunta0
Your filter is an array, not an object. Try:
const { column, comparison, value } = filter[0];
Or you can destrcuture your filter array and then do the object destructiong:
const [firstItem] = filter;
const { column, comparison, value } = firstItem;
0
Based on your latest screenshot of the entire component, the problem is that you are destructuring the filterByNumericValues array before it is hydrated with the data. Then your console.log has the correct data because it is in the useEffect hook AFTER the state has been updated with the data.
Since it looks like you are only using the column, comparison, and value variables in the checkFilterByNumeric function, I would destructure the state in that scope.
function checkFilterByNumeric(planet) {
const { column, comparison, value } = filterByNumericValues[0];
if (comparison === "maior que") {
...
}
0
You can do this, for example:
const defaultValue = { column: 'empty', comparison: 'empty', value: 0 }
const { column, comparison, value } = filter[0] || defaultValue;