小编use*_*660的帖子

如何将以下代码转换为java8中的lambda ???

    List<List<String>> my2dList = new ArrayList<List<String>>();
    int counter = 0;
    for (int i = 0; i < 5; i++) {
        my2dList.add(new ArrayList<String>());
        for (int j = 0; j < 10; j++) {
            System.out.println("Counter: " +counter);
            my2dList.get(i).add(new String(""+counter));
            counter++;
        }
    }

预期结果:

[[0,1,2,3,4,5,6,7,8,9],[10,11,12,13,14,15,16,17,18,19],[20,21, 22,23,24,25,26,27,28,29],[30,31,32,33,34,35,36,37,38,39],[40,41,42,43,44, 45,46,47,48,49]]

我正在尝试编辑txt文件中的第一行,但由于某种原因,它将用空格字符替换下一行...

int main()
{
  FILE *myFile;
  myFile = fopen("test.txt", "r+");
  fprintf(myFile, "Hello\n");
  fclose(myFile);
}

运行代码前的txt文件:

i
like
this

运行代码后的txt文件:

Hello

this