java - Java 中的类型转换

Question

我想知道是否有一种方法可以在java中将整数数组转换为字符数组。我不断收到 nullPointer Exception 错误。

这就是我所拥有的......

    private char [] clubsArray; // Will hold the clubsString String as an array 
        private char [] heartsArray;// Will hold the heartsString String as an array
        private char [] spadesArray;// Will hold the spadesString String as an array
        private char [] diamondsArray;// Will hold the diamondsString String as an array
    private int [] intClubsArray; // Holds the character array as number values so I can sort it properly 
        private int [] intHeartsArray; // Holds the character array as number values so I can sort it properly 
        private int [] intSpadesArray; // Holds the character array as number values so I can sort it properly 
        private int [] intDiamondsArray; // Holds the character array as number values so I can sort it properly 


public void cast()
    {
        for (int i = 0; i < clubsArray.length; i++)// A loop that will cast all the clubs into ints 
        {
            intClubsArray[i] = (int) clubsArray[i];
        }
        for (int i = 0; i < heartsArray.length; i++)// A loop that will cast all the hearts into ints 
        {
            intHeartsArray[i] = (int) heartsArray[i];
        }
        for (int i = 0; i < spadesArray.length; i++)// A loop that will cast all the spades into ints 
        {
            intSpadesArray[i] = (int) spadesArray[i];
        }
        for (int i = 0; i < diamondsArray.length; i++)// A loop that will cast all the diamonds into ints 
        {
            intDiamondsArray[i] = (int) diamondsArray[i];
        }
    }

为什么我会收到此错误？可以修好吗？？我可以转换整个数组吗？此外，我不想为变量设置特定的大小，因为当它变成 int [] 时，我会在空白处得到不必要的 0 。

Answer 1

错误是在 clubsArray.length 处吗？

如果是这样，那是因为您还没有执行以下操作:

clubsArray = new char[12];

您也可能无法初始化 intClubsArray 或任何其他数组)