Question

我有一个数组，我正在尝试根据另一个数组对该数组重新排序。第二个数组是索引数组（请参见下文）。我正在寻找一个干净的函数来接受两个参数（一个数组和一个索引数组），并返回重新排序的数组。我尝试构建此函数并在下面提供示例，但是它没有返回我期望的结果。任何帮助是极大的赞赏。

var before = ["T", "T", "A", "T", "T", "T", "T", "T", "A", "T", "T","T", "W", "W", "W", "W", "T", "T", "T", "T", "T", "W", "T"];
var indexes = [8, 2, 11, 22, 0, 4, 5, 18, 6, 17, 16, 19, 7, 3, 20, 1, 10, 9, 14, 13, 21, 12, 15];

// Attempt
function reorderArray(arrayToOrder ,order){
    // Get a copy of the array we want to change
    var temp = arrayToOrder
    // loop through the indexes
    // use the indexes to place the items in the right place from the copy into the original
    for(let i = 0; i < arrayToOrder.length; i++) {
        console.log("arr: ", arrayToOrder[order[i]] );
        console.log("temp: ", temp[i] );
        arrayToOrder[order[i]] = temp[i];
    }
    return arrayToOrder;
}
// run function
reorderArray( before, indexes );

// function should return this array
var after = ["A", "A", "T", "T", "T", "T", "T", "T", "T", "T", "T", "T", "T", "T", "T", "T", "T", "T", "W", "W", "W", "W", "W"];

Answer 1

您可以使用Array.prototype.map

var before = ["T", "T", "A", "T", "T", "T", "T", "T", "A", "T", "T","T", "W", "W", "W", "W", "T", "T", "T", "T", "T", "W", "T"];
var indexes = [8, 2, 11, 22, 0, 4, 5, 18, 6, 17, 16, 19, 7, 3, 20, 1, 10, 9, 14, 13, 21, 12, 15];

var output = indexes.map(i => before[i]);

console.log(output);

Answer 2

用indexes迭代Array.map()，然后从before数组返回值：

const before = ["T", "T", "A", "T", "T", "T", "T", "T", "A", "T", "T","T", "W", "W", "W", "W", "T", "T", "T", "T", "T", "W", "T"];
const indexes = [8, 2, 11, 22, 0, 4, 5, 18, 6, 17, 16, 19, 7, 3, 20, 1, 10, 9, 14, 13, 21, 12, 15];

const reorderByIndexes = (arr, order) => order.map((index) => arr[index]);
  
const after = reorderByIndexes(before, indexes);

console.log(after.join());

Answer 3

或者如果您不想使用ES6，请使用forEach

var before = ["T", "T", "A", "T", "T", "T", "T", "T", "A", "T", "T", "T", "W", "W", "W", "W", "T", "T", "T", "T", "T", "W", "T"];
var indexes = [8, 2, 11, 22, 0, 4, 5, 18, 6, 17, 16, 19, 7, 3, 20, 1, 10, 9, 14, 13, 21, 12, 15];
var after = [];
indexes.forEach(function(value, index) {
  after[index] = before[value]
})

console.log(after)

使用javascript通过索引重新排序数组

3 个答案: