如何以正确的顺序显示数字/字符串？

Question

我有一些作业需要帮助。所以我不得不编写代码，其中给了我三个数字，并且通过使用 if-else 语句，我必须以正确的顺序显示它们。所以我认为我在正确的数字道路上，但不知道如何使用字符串来显示它。这是我到目前为止所做的：

public class CS1702_Lab32 
{   
    static public void main(String args[])  
    {
        int a = 9, b = -10, c = -3;

    /* These are the six possible orders
     * abc
     * acb
     * bac
     * bca
     * cab
     * cba
     */

    if ( ( a <= b ) && ( b <= c ) )
    {
        System.out.println("The correct order is 'a'<='b'<='c'");
    }
    else if ( ( a <= c ) && ( c <= b ) )
    {
        System.out.println("The correct order is 'a'<='c'<='b'");
    }
    else if ( ( b <= a ) && ( a <= c ) )
    {
        System.out.println("The correct order is 'b'<='a'<='c'");
    }
    else if ( ( b <= c ) && ( c <= a ))
    {
        System.out.println("The correct order is 'b'<='c'<='a'");
    }
    else if ( ( c <= a) && ( a <= b ))
    {
        System.out.println("The correct order is 'c'<='a'<='b'");
    }
    else
    {
        System.out.println("The correct order is 'c'<='b'<='a'");
    }

    }
}

现在我将如何按字母顺序对三个字符串做同样的事情？我认为我现在不应该使用数组，因为工作表只是在条件语句上。以下是工作表中的问题（如果有帮助）：

Write the Java code that will solve the following problems:

1. Given three numbers, displays them in the correct order (ascending)
2. Given three names (e.g. name1, name2 and name3 as string variables), display them in the correct alphabetical order

Answer 1

String.compareTo 是你想要的。

http://docs.oracle.com/javase/6/docs/api/java/lang/String.html#compareTo%28java.lang.String%29

Answer 2

你可以使用Arrays.sort():

int[] numbers = {-40, 2, -5};
Arrays.sort(numbers);
System.out.println(Arrays.toString(numbers));

字符串也是如此：

String[] names = {"Me", "You", "ABC"};
Arrays.sort(names);
System.out.println(Arrays.toString(names));

Answer 3

错误在于这种情况：

else if ( ( c <= b) && ( a <= b ))
    {
        System.out.println("The correct order is 'c'<='a'<='b'");
    }

通过此检查，您的意思是：c 和 a 小于或等于 (<=) 到 b。其中，c 可以大于或小于a。

应该是else if ( ( c <= a) && ( a <= b ))发言：c <= a和a <= b：c <= a <= b

对于您指定的问题，请尝试sorting他们。

Answer 4

 int[] num = {11, 2, 3};

 /*Convert the array into a list*/
   ArrayList<Integer> list = new ArrayList<Integer>(Arrays.aslist(num));

/*Sort the list*/
   Collections.sort(list);

/*Same for String*/ 
   String[] str = {"b", "a", "c"};
   Arryslist<String> list2 = new ARrayList<String>(Arrays.aslist(str));

/*Sort the list*/
  Collections.sort(list2);