根据第一个数组重新排列数组[重复]答案

【问题标题】：Rearrange an arraay based on first array [duplicate]根据第一个数组重新排列数组[重复]
【发布时间】：2020-02-21 16:28:12
【问题描述】：

我有 2 个这样的数组：

array1 = ["green", "blue", "red"];
array2 = ["green", "green", "red", "red", "green", "green", "blue", "red", "Blue"];

但我需要类似的输出

output_array = ["green", "green", "green", "green", "blue", "Blue", "red", "red", "red"];

【问题讨论】：

稀疏的部分呢？你试过什么？
你的算法是什么？你想组合这些数组吗？您是否尝试在array1 中的方案之后对array2 进行排序？请说明。

标签： javascript arrays

【解决方案1】：

您可以将sort 与indexOf 一起使用：

const arr1 = ["green", "blue", "red"]
const arr2 = ["green", "green", "red", "red", "green", "green", "blue", "red", "blue"]

console.log(arr2.sort((a, b) => arr1.indexOf(a) - arr1.indexOf(b)))

【讨论】：

【解决方案2】：

我不知道你的意思是不是按字母顺序，但你可以合并两个数组，然后对结果进行排序：

let output_array = array1.concat(array2);

output_array.sort()

【讨论】：

【解决方案3】：

希望这对您有所帮助！

    array1=["green","red","blue"]; 
    array2=["green","green","red","red","green","green","blue","red","Blue"];

    const map = array2.reduce((acc, e) => acc.set(e, (acc.get(e) || 0) + 1), new Map());
    let result = array1.reduce((acc, a)=>  [...acc, ...Array(map.get(a)).fill(a)] , []);
    console.log(result);

【讨论】：