CODEWITHSUNDEEP
javascriptarraysreactjssyntax-errortypeerror
Jack Venevankham
Jack Venevankham

Reputation: 167

Reactjs: How to check each of array index containing the value or not?

This is my array:

  const [arr, setArr] = React.useState([
   {
     "id": 1,
     "barcode": "8851907264888",
     "qty" : 1
   }, 
   {
     "id": 2,
     "barcode": "8857124022072",
     "qty": 1
   }
  ]);

this is my function:

  const hasBarcode = (arr, barcode) => arr.some(el => el.barcode === barcode);

  const handleUpdate=()=>{
   let x = 8851907264888;
   for(let i = 0;i < arr.length;i++){
     if(hasBarcode(arr[i], x) == true){
        let newArr = [...arr];
        newArr[i].qty = newArr[i].qty + 1;
        setArr(newArr);       
       }
    }
  }

My problem is in the for loop, I would like to check each of array index, if each index contains the same barcodeas x, i would like to make addtion for qty + 1 for that specific index. But here it shown error as Cannot read property 'some' of undefined

Upvotes: 0

Views: 57

Answers (3)

Apostolos
Apostolos

Reputation: 10498

The error in your code is here

if(hasBarcode(arr[i], x) == true){

because you are trying to apply a method whose first argument is an array, to an object.

The correct one should be if(hasBarcode(arr, x) == true){

You could do the following, though, using filter and forEach functions of Array:

  const handleUpdate = () => {
    let x = 8851907264888;
    let newArr = [...arr];
    newArr.filter(el => el.barcode === barcode).forEach(el => el.qty++);
    setArr(newArr);  
  }

Upvotes: 2

Moufeed Juboqji
Moufeed Juboqji

Reputation: 700

the error in your code you passing an object to hasBarcode() not array also you can do it like this

  const handleUpdate = () => {
    let x = 8851907264888;
    let newArr = arr.map((obj) => {
      if (obj.barcode && obj.barcode == x) {
        obj.qty = obj.qty + 1;
      }
      return obj;
    });
    setArr(newArr);
  };

Upvotes: 3

Asutosh
Asutosh

Reputation: 1828

  const hasBarcode = (arr, barcode) => arr.some(el => el.barcode === barcode);

  const handleUpdate=()=>{
   let x = 8851907264888;
   for(let i = 0;i < arr.length;i++){
     if(hasBarcode(arr, x) == true){
        let newArr = [...arr];
        newArr[i].qty = newArr[i].qty + 1;
        setArr(newArr);       
       }
    }
  }

Upvotes: 2

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