CODEWITHSUNDEEP
reactjs
Rye
Rye

Reputation: 189

Remove specific value in array and add new updated value

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>

Upvotes: 2

Views: 5608

Answers (1)

helloitsjoe
helloitsjoe

Reputation: 6529

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);
     }

Upvotes: 1

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