Question

基本上，我需要搜索索引的下一个空值（指定为0），并用各种信息替换整行。例如，如果第三行中有空白元素，而不是“0,0,0,0”，则它将是“（行号），a，b，c”。这是我到目前为止，我只是得到一长串的运行时错误

String[][] clientsArray = new String[20][4];
int rows = 20;
int columns = 4;

for (int r = 0; r < rows ; r++ )
    {
        for (int c = 0; c < columns ; c++ )
            {
                if (clientsArray[r][c].equals ("0"))
                {
                    String key = Integer.toString(r);
                    clientsArray[r][0] = key;
                    clientsArray[r][0+1] = "a"
                    clientsArray[r][0+2] = "b"
                    clientsArray[r][0+3] = "c"
                    break;
                }
             }
    }

目前，整个2d数组都填充了'0'，我只是没有包含那段代码。

**注意：我已将'c'的值更改为0

Answer 1

从评论来看，您希望：

搜索2D数组，查找第1列为“0”的第一行。

然后您想要替换该行中的每个元素。

String[][] clientsArray = new String[20][4];
int rows = 20; // this can also be clientsArray.length
int columns = 4; // this can also be clientsArray[0].length

for (int r = 0; r < rows ; r++ )
{
    //since you are only looking at the 1st column, you don't need the inner loop
       // this makes sure that the spot in the 2d array is set, otherwise trying to call .equals will crash your program.
       if (clientsArray[r][0] == null || clientsArray[r][0].equals ("0")) 
       {
          String key = Integer.toString(r);
          clientsArray[r][0] = key;
          clientsArray[r][1] = "a"
          clientsArray[r][2] = "b"
          clientsArray[r][3] = "c"   //you don't need the 0+, if you wanted to have a 2d array with more then 4 rows, you could put a for loop here insead of doing it 4 times like you did here
          break; //if you wanted to find ALL empty rows take this out.
          //also note if you have 2 loops like in your question, if would only break out of the 1st one
       }   
}

扫描2d数组中的下一个空值并替换行中的值

1 个答案: