java - 按字母顺序正确排序数组时出现问题

Question

我的部分代码有问题。它必须按名称按字母顺序排序，但似乎是按降序排列的。有人可以指导我应该进行哪些更改才能使输出正确显示数据吗？谢谢。

这是我的排序代码:

//Method sortName
            public static void sortName() throws IOException {

            //Selection Sort
            for (x = 0; x < 8; x++) {
                smallest = x;

            for(i = x + 1; i < 8; i++) {

                //Compare current smallest
                //to the current position in the array
                if(name[i].compareTo(name[smallest])> 0) {
                    smallest = i;
                }

            }
                //Swap smallest element with position in array      
                temp = name [x];
                name [x] = name [smallest];
                name [smallest] = temp;

                temp = crime [x];
                crime [x] = crime [smallest];
                crime [smallest] = temp;

                temp = year [x];
                year [x] = year [smallest];
                year [smallest] = temp;

            }
            //Display each category of records; names, crime, year
            System.out.print("Name" + " ----" + "Crime" + "----" + "Year\n");

            //output
            for (x = 0; x < 8; x++) {

                //Display each sorted criminal name with the crime and year. 
                System.out.println(name[x] + " --- " + crime[x] + " --- " + year[x]);

这是我的输出:

Name ----Crime----Year
Slippery Sal --- Arson --- 1997
Natasha Ora --- Theft --- 2007
Kate Olaf --- Assault --- 1984
Eddie Striker --- Arson --- 1978
Bugs Malone --- Theft --- 1981
Bob Allen --- Assault --- 1957
Anne Wilson --- Arson --- 2013

Answer 1

看看compareTo javadoc 。它指出:

Returns: a negative integer, zero, or a positive integer as this object is less than, equal to, or greater than the specified object.

在你的行中

if(name[i].compareTo(name[smallest])> 0) {

提到的“这个对象”是name[i]而“指定对象”为name[smallest] 。而你想兑换的时候 name[i] 小于 name[smallest] 。所以要么你交换 name[i]和name[smallest] ，或者将比较更改为 < 0 .

此外，我始终建议在第一次测试时使用调试器逐步执行代码，尤其是在出现意外行为时。