排序 ArrayList [英] Sorting ArrayList

问题描述

因为我刚开始接触 JAVA，所以我很好奇在 JAVA 中实现排序的最佳选择是什么(对于 ArrayLists).下面我提供我的 PHP 代码.

Since I'm just starting with JAVA, I'm curious what is the best option for implementing sorting in JAVA (for ArrayLists). Below I provide my PHP code.

public int cmp($a, $b) {
    if ( $a[0] < $b[0] ) return 1;
    else if ( $a[0] > $b[0] ) return -1;
    else if ( $a[1] < $b[1] ) return 1;
    else if ( $a[1] > $b[1] ) return -1;
    else return 0;
}

$selected = array();

for ($i=0; $i<$len; $i++) {
    $rank = getRank();
    $cub = getCub_len();
    $selected[] = array($rank,$cub);
}

uasort($selected, 'cmp')

好吧，我用JAVA写了以下代码:

Well, I wrote the following code in JAVA:

ArrayList<ArrayList<Double>> selected = new ArrayList<ArrayList<Double>>();
ArrayList<Double> rank = new ArrayList<Double>();
ArrayList<Double> cub = new ArrayList<Double>();

for (int i=0; i<len; i++) {
 rank.add(getRank(i));
 cub.add(getCub(i));
}

selected.add(0,rank);
selected.add(1,cub);

如何以正确的方式对selected进行排序(类似于PHP函数cmp)?

How to sort selected in the proper way (similarly to PHP function cmp)?

推荐答案

在你的例子上试试这种方式: >

public static void main(String[] args) throws Exception {
        ArrayList<String[]> listOfStringArrays = new ArrayList<String[]>();
        listOfStringArrays.add(new String[] {"x","y","z"});
        listOfStringArrays.add(new String[] {"a","b","c"});
        listOfStringArrays.add(new String[] {"m","n","o"});
        Collections.sort(listOfStringArrays,new Comparator<String[]>() {
            public int compare(String[] strings, String[] otherStrings) {
                return strings[1].compareTo(otherStrings[1]);
            }
        });
        for (String[] sa : listOfStringArrays) {
            System.out.println(Arrays.toString(sa));
        }
        /* prints out 
          [a, b, c]
          [m, n, o]
          [x, y, z]
        */ 

    }

这篇关于排序 ArrayList的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！