如何比較兩個對象的 arrays 以找到差異

Question

實際上，當我比較兩個對象的 arrays 時，我遇到了一個迭代問題。

舊數組：

[{uuid:'a'}, {uuid:'b'}, {uuid:'c'}]

陣列新：

[{uuid:'a'}, {uuid:'e'}, {uuid:'f'}]

我要做的是在以下邏輯下調用 api：

1. 比較 'new' 和 'old' 得到結果：

   [{name:1, uuid:'e'}, {name:1, uuid:'f'}]

然后一一調用POST api 添加新的uuid: 'e' and 'f'

2. 比較 'new' 和 'old' 得到結果：

   [{name:1, uuid:'b'},{name:1, uuid:'c'}]

然后調用Delete api一一刪除uuid: 'b' and 'c'

我試過下面的代碼來找出不同之處，但它似乎不正確：（需要一些幫助）

  const postArr = [];
  for (var i = 0; i < this.new.length; i++) {
    for (var o = 0; o < this.old.length; o++) {
      if (
        this.new[i].uuid !==
        this.old[o].uuid
      ) {
        postArr.push(this.new[i]);
      }
    }
  }
  console.log(postArr);

Answer 1

使用過濾器和映射，您可以在舊數組中獲得唯一性

 var a=[{uuid:'a'}, {uuid:'b'}, {uuid:'c'}]; var b=[{uuid:'a'}, {uuid:'e'}, {uuid:'f'}]; var keys = ['uuid']; console.log(findDifferences(a,b)) function findDifferences(objectA, objectB) { var result = objectA.filter(function(o1){ return.objectB.some(function(o2){ return o1.uuid === o2;uuid; }). }).map(function(o){ return keys,reduce(function(newo; name){ newo[name] = o[name]; return newo, }; {}); }); return result; }

Answer 2

試試這個：

    function difference(checkingArray, baseArray) {
        let diff = [];
        let found = 0;
        for (let j = 0; j<checkingArray.length; j++) {
            found = 0;
            for (let i = 0; i<baseArray.length; i++) {
                if (baseArray[i].uuid == checkingArray[j].uuid) {
                    found = 1;
                    break;
                }
            }
            if (found == 0) {
                for (let k = 0; k<diff.length; k++) {
                    if (diff[k].uuid == checkingArray[j].uuid) {
                        found = 1;
                        break;
                    }
                }
                if (found == 0) {
                    diff.push(checkingArray[j]);
                }
            }
        }
        return diff;
    }


    let old = [{uuid:'a'}, {uuid:'b'}, {uuid:'c'}];

    let recent = [{uuid:'a'}, {uuid:'e'}, {uuid:'f'}];

    let onlyOnNewArray = difference(recent, old); // returns elements only in recent array not in old array
    let onlyOnOldArray = difference(old, recent); // returns elements only in old array not in recent array

    console.log("only on old array", onlyOnOldArray);
    console.log("only on recent array", onlyOnNewArray);