how to use react.usestate for allray of objects code example
Example 1: How to add object in an array using useState
import React, { useState } from 'react';
function App() {
const [items, setItems] = useState([]);
const addMoreItem = () => {
setItems(prevItems => [...prevItems, {
id: prevItems.length,
value: getRandomNumber()
}]);
}
const getRandomNumber = () => {
return Math.random().toString().substring(2, 8);
}
return (
<div classname="App">
<h3>useState with an array in React Hooks - <a href="https://www.cluemediator.com">Clue Mediator</a></h3>
<br>
<button onclick="{addMoreItem}">Add More</button>
<br><br>
<label>Output:</label>
<pre>{JSON.stringify(items, null, 2)}</pre>
</div>
);
}
export default App;
Example 2: how to set value in array react hook usestate
const[array,setArray]= useState([
{id: 1, value: "a string", othervalue: ""},
{id: 2, value: "another string", othervalue: ""},
{id: 3, value: "a string", othervalue: ""},
])
const updateItem =(id, whichvalue, newvalue)=> {
var index = array.findIndex(x=> x.id === id);
let g = array[index]
g[whichvalue] = newvalue
if (index === -1){
console.log('no match')
}
else
setArray([
...array.slice(0,index),
g,
...array.slice(index+1)
]
);
}
onPress={()=>updateItem(2,'value','ewfwf')}
onPress={()=>updateItem(1,'othervalue','ewfwf')}