Question

我正在尝试学习并从7开始转换到Java 8 当我在切换Arrays.sort时出现问题，这给出了我的错误：type不适用我知道有一些更好的方法可以完成相同的任务，但我想使用相同的功能来更好地理解提前谢谢。

package src;

import java.util.Arrays;
import java.util.Comparator;

public class Java8Learning {
    public static void main(String[] args){
        Integer[] numbers = {4,5,3,2,6,1};
        -------java 7 ---------
        Arrays.sort(numbers, new Comparator<Integer>() {
            @Override
            public int compare(Integer firstNumber, Integer secondNumber){
                System.out.print("comparing :"+ firstNumber + " and " + secondNumber);
                return Integer.compare(firstNumber, secondNumber);
            }
        });
        -------java 8 ---------
        // it gave me error
        //The method sort(T[], Comparator<? super T>) in the type Arrays is not applicable for the arguments (Integer[], (<no type> firstNumber, <no type> secondNumber) -> {})
        Arrays.sort(numbers, (firstNumber, secondNumber) -> 
                                 {  System.out.print("comparing :"+ firstNumber + " and " + secondNumber);
                                     Integer.compare(firstNumber, secondNumber);
                                 });

    }
}

Answer 1

错过了Integer.compare

之前的回复

Arrays.sort(numbers, (firstNumber, secondNumber) -> 
                     {  System.out.print("comparing :"+ firstNumber + " and " + secondNumber);
                        return Integer.compare(firstNumber, secondNumber);
                     });

使用带有Lambda的Arrays.sort

1 个答案: