如何比较两个数组并删除不匹配的记录答案

【问题标题】：How to compare two arrays and remove unmatched record如何比较两个数组并删除不匹配的记录
【发布时间】：2021-03-01 04:59:52
【问题描述】：

我有两个数组，我想通过对象索引 {index:...} 比较两个数组。如果索引不匹配，那么我想从数组中删除该对象。

数组 1

[
Text Field 32: {fieldName: "Text Field 32", fieldType: "text", index: 0, data: "valu1"},
Text Field 53: {fieldName: "Text Field 53", fieldType: "text", index: 1, data: ""},
Text Field 64: {fieldName: "Text Field 64", fieldType: "text", index: 2, data: "value 3"},
Text Field 65: {fieldName: "Text Field 65", fieldType: "text", index: 3, data: "value 4"}
]

数组 2

[
Text Field 32: {fieldName: "Text Field 32", fieldType: "text", index: 0, data: ""},
Text Field 64: {fieldName: "Text Field 64", fieldType: "text", index: 2, data: ""},
Text Field 65: {fieldName: "Text Field 65", fieldType: "text", index: 3, data: ""}
]

注意：正如您在数组 2 中看到的 {index:1} 缺失。有人可以帮助我如何删除不匹配的对象。

预期结果

  [
    Text Field 32: {fieldName: "Text Field 32", fieldType: "text", index: 0, data: "valu1"},
    Text Field 64: {fieldName: "Text Field 64", fieldType: "text", index: 2, data: "value 3"},
    Text Field 65: {fieldName: "Text Field 65", fieldType: "text", index: 3, data: "value 4"}
    ]

【问题讨论】：

嗨，您需要从数组 1 中删除对象吗？

标签： javascript arrays reactjs ecmascript-6

【解决方案1】：

这个函数接受两个数组，left 和 right。它返回左过滤以仅包含右数组的indexs 中具有indexs 的项目。

function matching(left, right) {
    const right_indices = right.map(r=>r.index);
    return left.filter(l=>right_indices.includes(l.index))
}

请注意，我不是修改原始数组。

所以，如果你有：


var Array1 = [...blahblah];
var Array2 = [...blahblah];

// You need to reassign Array1:

Array1 = matching(Array1, Array2);

【讨论】：

【解决方案2】：

const arr1: any = [
{fieldName: "Text Field 32", fieldType: "text", index: 0, data: "valu1"},
{fieldName: "Text Field 53", fieldType: "text", index: 1, data: ""},
{fieldName: "Text Field 64", fieldType: "text", index: 2, data: "value 3"},
{fieldName: "Text Field 65", fieldType: "text", index: 3, data: "value 4"}
]

const arr2: any  = [
{fieldName: "Text Field 32", fieldType: "text", index: 0, data: ""},
{fieldName: "Text Field 64", fieldType: "text", index: 2, data: ""},
{fieldName: "Text Field 65", fieldType: "text", index: 3, data: ""}
]



const updatedArr = arr1.map((arrItem: any) => {
    const sameValue = arr2.find((arr2Item: any) => {
        return arrItem.index === arr2Item.index
    })
    if (sameValue) return sameValue 
})

console.log(updatedArr)

【讨论】：

这种方法在结果数组中生成undefined 项，而不是删除它们。
这很奇怪，因为我在操场上进行了测试，它返回了正确的结果数组

【解决方案3】：

你可以这样做：

var firstArray = [
 {fieldName: "Text Field 32", fieldType: "text", index: 0, data: "valu1"},
 {fieldName: "Text Field 53", fieldType: "text", index: 1, data: ""},
 {fieldName: "Text Field 64", fieldType: "text", index: 2, data: "value 3"},
 {fieldName: "Text Field 65", fieldType: "text", index: 3, data: "value 4"}
];

var secondArray = [
 {fieldName: "Text Field 32", fieldType: "text", index: 0, data: ""},
 {fieldName: "Text Field 64", fieldType: "text", index: 2, data: ""},
 {fieldName: "Text Field 65", fieldType: "text", index: 3, data: ""}
]

var result = secondArray.filter(x => firstArray.find(y=>y.index == x.index));


console.log(result)

【讨论】：

可能想把id换成index。