我有一个二维 double 组,我想根据第二列对其进行排序。我编写了这段代码,但在最后一行“无法取消引用 double ”时出现此错误。它似乎适用于字符串,但不适用于数组。任何帮助表示赞赏。
import java.util.Arrays;
import java.util.Comparator;
public class Sort {
public static void main(String args[]){
//Array to sort
double[][] X = new double[][]{
{1.2,2,1,3.1},
{1,2.7,3.3},
{1,2.3,3.1},
{1.5,3.2,2.4};
//Sort the array by column 2
Arrays.sort(X, new ColumnComparator(2));
}
}
//Class that extends Comparator
class ColumnComparator implements Comparator {
int columnToSort;
ColumnComparator(int columnToSort) {
this.columnToSort = columnToSort;
}
//overriding compare method
public int compare(Object o1, Object o2) {
double[] row1 = (double[]) o1;
double[] row2 = (double[]) o2;
//compare the columns to sort
return row1[columnToSort].compareTo(row2[columnToSort]);
}
最佳答案
public class SecondColumnComparator implements Comparator<double[]> {
@Override
public int compare(double[] row1, double[] row2) {
return Double.compare(row1[1], row2[1]);
// or, before Java 7:
// return Double.valueOf(row1[1]).compareTo(Double.valueOf(row2[1]));
}
}
关于java - 对二维数组进行排序,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/15422091/