arrays - 搜索包含项目数组的项目等node.js

Question

想象一下，我有一个项目，它有一个项目数组，并且该数组中的任何项目都有一个项目数组，依此类推。所以我有无限级别的 Items，我想知道如何在 Node.js 中访问所有这些 Items。像这样:

    Item1
     /     \
   Item2    Item3
            /    \
          Item4   Item5

Item1 是一个数组。Item2 和 Item3 另一个数组等等。

Answer 1

I have an Item that has an array of Items ... i want to know how to get to all of them

如果数组是数组，则递归地展平数组中的每个元素，否则追加它。

/* setup test input */
const tree = [
  "leaf_A_1",
  "leaf_A_2",
  [
    "leaf_B_1",
    "leaf_B_2",
    [
      "leaf_C_1",
      "leaf_C_2",
    ]
  ]
]
console.log("INPUT:\n", tree)

/* run test */
const leaves = flatten(tree)
console.log("OUTPUT:", leaves) // outputs leaf nodes in a flat array

// flatten() is a recursive function takes an array that *may* contain nested arrays, and returns an array containing all leaf elements without nesting.
function flatten(arr) {
  return arr.reduce(expandNestedArraysOrAppend, [])
}

function expandNestedArraysOrAppend(accum, element, idx) {
  if (Array.isArray(element)) {
    return [...accum, ...flatten(element)] // if we have an array, flatten it before appending
  }
  return [...accum, element]               // if not an array, just append
}

希望这有帮助。干杯!