根据特定索引中的 2 个或更多值过滤嵌套数组

Question

我有一个简单的嵌套数组，如下所示：

var test_array = [["0", "0.1", "4.2", "Kramer Street"], ["1", "0.2", "3.5", "Lamar Avenue"], ["3", "4.2", "7.1", "Kramer Street"]];

每个子数组都有 0 - 3 的索引。假设我想要一个函数来获取索引 2 的值，其中索引 1 =“4.2”，索引 3 =“Kramer Street”。我知道我可以使用类似下面的东西来 return 匹配 ["4.2", "Kramer Street"] 的子数组，但在我的问题中，这很棘手，因为从技术上讲，它 returns 2 个子数组我只想要一个基于指定索引的匹配项：

var test_array = [
  ["0", "0.1", "4.2", "Kramer Street"],
  ["1", "0.2", "3.5", "Lamar Avenue"],
  ["3", "4.2", "7.1", "Kramer Street"]
];

function matcher(array1, array2) {
  return array1.every(value => array2.includes(value));
}

function array_parser(array, keywords) {
  return array.filter(values => matcher(keywords, values));
}

var new_array = array_parser(test_array, ["4.2", "Kramer Street"]);

console.log(new_array);

Answer 1

您可以使用Array.find

var test_array = [
  ["0", "0.1", "4.2", "Kramer Street"],
  ["1", "0.2", "3.5", "Lamar Avenue"],
  ["3", "4.2", "7.1", "Kramer Street"]
];

test_array.find(arr => arr[1] === "4.2" && arr[3] === "Kramer Street")[2]

Answer 2

因为你想过滤一个索引和值匹配的数组，传递一个对象作为第二个参数，其中属性是唯一索引，value是要匹配的字符串。由于数组索引本身是唯一的，因此对象是最合适的，因为它的属性也必须是唯一的。

比使用组合：Array.prototype.filter, Array.prototype.every and finally match by Object.entries 对：

/**
 * Filter Array of sub-Arrays where "indexes have value"
 * @param {Array} arr Array to filter
 * @param {Object} ob Object with index/value pairs
 * @return {Array} A filtered array of subarrays.
 */
const filterByIndexValue = (arr, ob) =>
  arr.filter(sub => Object.entries(ob).every(([i, v]) => sub[i] === v));


// DEMO TIME:
const test_array = [
  ["0",  "0.1", "4.2",  "Kramer Street"],
  ["3",  "4.2", "7.1",  "Kramer Street"],  // << get this one
  ["6",  "0.2", "3.5",  "Lamar Avenue"],
  ["99", "4.2", "99.1", "Kramer Street"],  // << get this one
];

// Filter test_array where sub-arrays
// index 1 has value "4.2" and
// index 3 has value "Kramer Street"

const new_array = filterByIndexValue(test_array, {
  1: "4.2",
  3: "Kramer Street"
});
console.log(new_array);

根据特定索引中的 2 个或更多值过滤嵌套数组

Filtering a nested array based on 2 or more values in specific indices

javascript

arrays

filter

indices