# V3225\. A data reading method returns the number of bytes that were read and cannot return the value of \-1\.

The analyzer has detected a possible incorrect check of the method's return value\. Some methods return values that indicate successful execution\. Developers may expect the method to return \-1, but it actually returns 0\.

The example:

```cpp
public void ProcessStream(Stream s)
{
  byte[] bytes = new byte[s.Length + 10];
  int numBytesRead = 0;
  int n = s.Read(bytes, numBytesRead, 1);
    
  if (n == -1)
  {
    ....
  }

  ....
}
```

In this case, the check of the method's return value is redundant because the `Read` method returns `0` at the end of the stream\.

The fixed code:

```cpp
public void ProcessStream(Stream s)
{
  byte[] bytes = new byte[s.Length + 10];
  int numBytesRead = 0;
  int n = s.Read(bytes, numBytesRead, 1);
    
  if (n == 0)
  {
    ....
  }

  ....
}
```