set array in an object using usestate code example

Example 1: 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){
    // handle error
    console.log('no match')
  }
  else
    setArray([
      ...array.slice(0,index),
      g,
      ...array.slice(index+1)
    ]
            );
}
//how to use the function    
onPress={()=>updateItem(2,'value','ewfwf')}
onPress={()=>updateItem(1,'othervalue','ewfwf')}
/*
the first input of the function is the id of the item
the second input of the function is the atrribute that you wish to change
the third input of the function is the new value for that attribute
It's a pleasure :0
~atlas
*/

Example 2: react setstate in hooks to array of objects value

// sample datas structure
/* const datas = [
    {
      id:   1,
      name: 'john',
      gender: 'm'
    }
    {
      id:   2,
      name: 'mary',
      gender: 'f'
    }
] */ // make sure to set the default value in the useState call (I already fixed it)

const [datas, setDatas] = useState([
    {
      id:   1,
      name: 'john',
      gender: 'm'
    }
    {
      id:   2,
      name: 'mary',
      gender: 'f'
    }
]);

const updateFieldChanged = index => e => {

    console.log('index: ' + index);
    console.log('property name: '+ e.target.name);
    let newArr = [...datas]; // copying the old datas array
    newArr[index] = e.target.value; // replace e.target.value with whatever you want to change it to

    setDatas(newArr); // ??
}

return (
    <React.Fragment>
        { datas.map( (data, index) => {
              <li key={data.name}>
                <input type="text" name="name" value={data.name} onChange={updateFieldChanged(index)}  />
              </li>
          })
        }
    </React.Fragment>
)