Remove specific value in array and add new updated value

Question

I'm trying to remove existing specific value in an array before adding or push another updated value. My purpose is to avoid duplicate same id and value to array. What i'm trying to achieve is when onchange triggered check if that value is existing on array and if exist remove the old one and push the update value.

  const [array, setnewarray] = useState([]);
     function handlechangeselected(val,id){

       var newarray = array;
       const valueToRemove = id;
       newarray.filter(item => item.id === valueToRemove);

        newarray.push({ value: val, id:id });
       setnewarray(newarray);

  }




  <select                                                                              
   onChange={(e) => handlechangeselected(e.target.value,row.ID)}                                                                                
  >

      <option value="0">0</option>                                                                             
      <option value="1">1</option>                                                                           
      <option value="2">2</option>

  </select>

helloitsjoe · Accepted Answer · 2019-06-22 03:09:41Z

1

The first issue is that filter doesn't modify the array, but rather returns a new array. You're not using the returned array, so newArray is unchanged.

The other issue is that filter filters out out any values that return false from your callback, so you want your filter to return true for any items that don't match valueToRemove (in other words, !== instead of ===). You can also use .concat to chain after array.filter.

Here it is, simplified a bit:

     const [array, setNewArray] = useState([]);

     function handlechangeselected(value, id){
       const newArray = array
         .filter(item => item.id !== id)
         .concat({ value, id });

       setNewArray(newArray);
     }

edited Jun 22, 2019 at 3:09

answered Jun 22, 2019 at 2:56

helloitsjoe

6,5393 gold badges24 silver badges34 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Remove specific value in array and add new updated value

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related