如何合并查找差异数组和数组json JavaScript？

Question

Anyone can help me with merge difference two array and array json . You can check my below code and result that I want to check difference between arr and arr2

First Array

let arr=[ '124', '125', '126', '127' ]

Second Array

let arr2=[{ 
            _id: '125',
            itemId: '125',
            onHand: 10,
            inventoryValue: 70,
            avgCost: 7 
          },
          { 
            _id: '124', 
            itemId: '124', 
            onHand: 10,
            inventoryValue: 50,
            avgCost: 5 
          } 
         ]

I want result like that

let arr3=['126', '127' ]

Answer 1

Just filter your arr based on whether arr2 does not include each value as an _id by using some :

 let arr = ['124', '125', '126', '127'] let arr2 = [{ _id: '125', itemId: '125', onHand: 10, inventoryValue: 70, avgCost: 7 }, { _id: '124', itemId: '124', onHand: 10, inventoryValue: 50, avgCost: 5 } ]; let arr3 = arr.filter(e => !arr2.some(({ _id }) => _id == e)); console.log(arr3); 

Answer 2

Find the index of all the ids od arr2 in arr1 and splice them form arr1

 let arr = ['124', '125', '126', '127']; let arr2 = [{ _id: '125', itemId: '125', onHand: 10, inventoryValue: 70, avgCost: 7 }, { _id: '124', itemId: '124', onHand: 10, inventoryValue: 50, avgCost: 5 } ]; arr2.forEach(function(element) { var index = arr.indexOf(element._id); if (index > -1) { arr.splice(index, 1); } }); console.log(arr);