我需要对包含重复项的列上的二维数组进行排序，将重复项移动到顶部。
我可以使用以下方法按降序对 2D 数组进行排序：
values.sort((a, b) => a[2].localeCompare(b[2]));
但是如何将重复项移动到顶部，并保持其排序顺序？
有
X1 Z9 [email protected]
X3 Z7 [email protected]
X4 Z6 [email protected]
X5 Z1 [email protected]
X5 Z7 [email protected]
X7 Z2 [email protected]
X8 Z6 [email protected]
X9 Z5 [email protected]
X9 Z8 [email protected]
排序后：
X5 Z1 [email protected]
X7 Z2 [email protected]
X9 Z5 [email protected]
X4 Z6 [email protected]
X8 Z6 [email protected]
X3 Z7 [email protected]
X5 Z7 [email protected]
X9 Z8 [email protected]
X1 Z9 [email protected]
需要
X7 Z2 [email protected]
X9 Z5 [email protected]
X4 Z6 [email protected]
X8 Z6 [email protected]
X3 Z7 [email protected]
X5 Z7 [email protected]
X5 Z1 [email protected]
X9 Z8 [email protected]
X1 Z9 [email protected]
我的方法是提取二维数组的最后一列，根据您的首选输出对其进行排序，然后根据该列对二维数组进行排序。
尝试这个代码片段：
function sortArray() {
var values = [ [ 'X1', 'Z9', '[email protected]' ],
[ 'X3', 'Z7', '[email protected]' ],
[ 'X4', 'Z6', '[email protected]' ],
[ 'X5', 'Z1', '[email protected]' ],
[ 'X5', 'Z7', '[email protected]' ],
[ 'X7', 'Z2', '[email protected]' ],
[ 'X8', 'Z6', '[email protected]' ],
[ 'X9', 'Z5', '[email protected]' ],
[ 'X9', 'Z8', '[email protected]' ] ];
//Extracts the the last column of the array
var lastCol = values.map(a => a[2])
//Extracts the duplicate elements of the last column
var dup = lastCol.filter(a => lastCol.indexOf(a) != lastCol.lastIndexOf(a)).sort()
//Extracts the unique elements of the last column
var unique = lastCol.filter(a => lastCol.indexOf(a) == lastCol.lastIndexOf(a)).sort()
//combines the duplicate and unique elements, sorted to the preferred output.
var sortOrder = dup.concat(unique);
//sorts the 2d array based on sorted last column
var sortedArray = values.sort((a,b) => sortOrder.indexOf(a[2]) - sortOrder.indexOf(b[2]))
console.log(sortedArray)
}