Question

我有10个String[]类型的数组。从这10个数组我想随机选择1个字符串。到目前为止，我已经创建了以下内容：

static final String[] puzzle1 = new String[] {"1" , "2" , "3" , "4" , "?" };
static final String[] puzzle2 = new String[] { "1" , "3" , "5" , "7" , "?"};
static final String[] puzzle3 = new String[] { "1" , "3" , "5" , "7" , "?"};
static final String[] puzzle4 = new String[] { "1" , "3" , "5" , "7" , "?"};
static final String[] puzzle5 = new String[] { "1" , "3" , "5" , "7" , "?"};


static final String[] select = new String[] { "puzzle1" , "puzzle2" , "puzzle3" ,
    "puzzle4" , "puzzle5"};

Random rand = new Random();
int selectedString = rand.nextInt(select.length);   
String selectedPuzzle = select[selectedString];

这允许我选择一个数组名称。但是我如何获得数组值呢？

Answer 1

从这10个数组中我想随机选择1个字符串。

您只需选择一个随机数组，然后选择该数组中的随机元素。诀窍是存储一个或多个数组，而不是数组名称数组。

static final String[] puzzle1 = { "1", "2", "3", "4", "?" };
static final String[] puzzle2 = { "1", "3", "5", "7", "?" };
static final String[] puzzle3 = { "1", "3", "5", "7", "?" };
static final String[] puzzle4 = { "1", "3", "5", "7", "?" };
static final String[] puzzle5 = { "1", "3", "5", "7", "?" };

static final String[][] allPuzzles = { puzzle1, puzzle2, puzzle3, puzzle4,
    puzzle5 };


public static String chooseRandomString() {
  Random rand = new Random();    
  String[] selectedPuzzle = allPuzzles[rand.nextInt(allPuzzles.length)];
  return selectedPuzzle[rand.nextInt(selectedPuzzle.length)];
}

Answer 2

简单的答案是

String thirdElementOfPuzzle2 = select[2];

但基本上你的select所指的是错误的

String [] select;

switch (selectedString ) {
     case :0
         select = puzzle1;
         break;
     case 1:
         select = puzzle2;

     //etc

目前

String selectedPuzzle = select[selectedString];

你得到的只是谜题的name。除非您使用反射，否则无法动态地使用名称访问数组，因此您必须进行相等性测试，例如如果我选择数字0然后给我第一个谜题，如果我选择1给我第二个谜题然后你可以将选择的谜题分配给一个通用数组，然后可以在你的代码中引用。

Answer 3

将Select数组更改为二维String[][]

将所有数组放在select[][]

中

从随机选择的数组中随机获取值

public static void main(String args[]){

         final String[] puzzle1 = new String[] {"1" , "2" , "3" , "4" , "?" };
         final String[] puzzle2 = new String[] { "1" , "3" , "5" , "7" , "?"};
         final String[] puzzle3 = new String[] { "1" , "3" , "5" , "7" , "?"};
         final String[] puzzle4 = new String[] { "1" , "3" , "5" , "7" , "?"};
         final String[] puzzle5 = new String[] { "1" , "3" , "5" , "7" , "?"};


         final String[][] select = new String[][] { puzzle1 , puzzle2 , puzzle3 , puzzle4 , puzzle5};

                    Random rand = new Random();
            int selectedString = rand.nextInt(select.length);   
            String selectedPuzzle = select[selectedString][selectedString];
            System.out.print(selectedPuzzle );

    }

Demo

如何从十个数组中选择一个随机元素？

3 个答案: