How to generate uniques after subtracting arrays' elements based on conditions using JS?-CodePudding

How to check if the item in array1 exists in array2 and, if so, subtract col4 from col5 to output th pending qty. If not, then, item's qty from array1 is the pending qty.

let array1 = 
[
 [1, "Item A", "Food", 10, 0],
 [2, "Item B", "Food", 5, 0],
 [3, "Item C", "Food", 30, 0]
]

let array2 = 
[
 [1, "Item A", "Food", 5, 3],
 [3, "Item C", "Food", 10, 5]
]

Expected Result

let res= 
[
 [1, "Item A", "Food", 10, 7],
 [2, "Item B", "Food", 5, 0],
 [3, "Item C", "Food", 30, 25]
]

I started it using for loops, but I was wondering what this would look like using map() or reduce()?

let array1 = [
  [1, "Item A", "Food", 10, 0],
  [2, "Item B", "Food", 5, 0],
  [3, "Item C", "Food", 30, 0]
]

let array2 = [
  [1, "Item A", "Food", 5, 3],
  [3, "Item C", "Food", 10, 5]
]

let result = [];
for (let a = 0; a < array1.length; a  ) {
  let item = [];
  for (let r = 0; r < array2.length; r  ) {
    if (array1[a][0] == array2[r][0] && array1[a][1] == array2[r][1]) {
      let pendingQty = array1[a][3] - array2[r][4];
      if (pendingQty > 0) {
        item = [array1[a][0], array2[r][1], array2[r][2], array2[r][3], pendingQty];
      } else {
        item = array1[a];
      }
    }
    if (item.length === 0) {
      item = array1[a];
    }
  }
  result.push(item.slice());
}
console.log(result)

Thanks

CodePudding user response：

let a1 = [ [1, "Item A", "Food", 10, 0], [2, "Item B", "Food", 5, 0], [3, "Item C", "Food", 30, 0]];
let a2 = [ [1, "Item A", "Food", 5, 3], [3, "Item C", "Food", 10, 5]];
console.log(a1.map(e=>[...e.slice(0,4),e[3]-(a2.find(j=>j[1]===e[1])?.[4]??0)]));