java - char 数组的值不断变化

Question

我有两个不同的二维数组，用于以以下形式存储 map :

 [#, #, #, #, #, #, #, #, #, #, #, #, #, #, #, #, #, #, #]
 [#, ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., #]
 [#, ., ., ., ., ., ., G, ., ., ., ., ., ., ., ., E, ., #]
 [#, ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., #]
 [#, ., ., E, ., ., ., ., ., ., ., ., ., ., ., ., ., ., #]
 [#, ., ., ., ., ., ., ., ., ., ., G, ., ., ., ., ., ., #]
 [#, ., ., ., ., ., ., ., ., ., ., ., ., ., P, ., ., ., #]
 [#, ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., #]
 [#, #, #, #, #, #, #, #, #, #, #, #, #, #, #, #, #, #, #]

我已将此分配给变量 mapArrayGlobal，但是当我调用方法 createBlankArray() 时，它似乎更改了此变量。我的类(class)完整代码如下:

 static int Column, Row, goldNumber;
int goldCount = 0;
char [][] mapArrayGlobal, mapBlank;
boolean goldMarker = false;
boolean exitSet = false;

public void setPosition(int rows, int column, char [][] TwoDArray, int goldValue){
    goldNumber = goldValue;
    Column = randInt(1, column - 1);
    Row = randInt(1, rows - 2);

    mapArrayGlobal = TwoDArray;
    mapBlank = mapArrayGlobal;

    if(mapArrayGlobal[Row][Column] == '#'){
        setPosition(rows, column, TwoDArray, goldValue);
    }
    else if(mapArrayGlobal[Row][Column] == 'G'){
        goldMarker = true;
        mapArrayGlobal[Row][Column] = 'P';
    }
    else{
        mapArrayGlobal[Row][Column] = 'P';
    }
    createBlankArray(TwoDArray);
}

public void createBlankArray(char [][] array){
    printArray(array);
    for(int i = 1; i < array.length - 1; i++){
        for(int j = 1; j < array[0].length - 1; j++){
            mapBlank[i][j] = '?';
        }   
    }
    printArray(mapBlank);
    printArray(mapArrayGlobal);
}

public static int randInt(int min, int max) {

    Random rand = new Random();

    int randomNum = rand.nextInt((max - min) + 1) + min;

    return randomNum;
}

在这段代码的最后，mapArrayGlobal 和 mapBlank 的值都是:

 [#, #, #, #, #, #, #, #, #, #, #, #, #, #, #, #, #, #, #]
 [#, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, #]
 [#, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, #]
 [#, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, #]
 [#, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, #]
 [#, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, #]
 [#, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, #]
 [#, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, #]
 [#, #, #, #, #, #, #, #, #, #, #, #, #, #, #, #, #, #, #]

谁能告诉我这是为什么。

非常感谢:)

Answer 1

您实际上是将 TwoDArray 变量的引用(的值)传递给 createBlankArray 方法。因为你有:

mapArrayGlobal = TwoDArray;
mapBlank = mapArrayGlobal;

mapBlank 指向 mapArrayGlobal，后者指向 TwoDArray，因此更改 mapBlank 会导致更改 TwoDArray 的元素。

顺便说一句，您不应该以大写字母开头变量/实例名称。命名变量的约定是 camelCase。