Description x y 2006-04-21 13:22:31 EDT

Most programmers would like to set 'Error' severity level for 1st case, but 'Warning' for 2nd & 3rd (or even ignore 3d).

1)
// The variable string can only be null; it was either set to null or checked for null when last used.
// This is DEFINITELY BAD code, since NPE would be thrown.
// Probably programmer meant: string != null && string.length() == 0
if (string == null && string.length() == 0)

2)
// The variable string may be null
// This is PROBABLY BAD code, since string can be null.
if (string.length() == 0)

3)        
// The variable string cannot be null; it was either set to a non-null value or assumed to be non-null when last used
// This is UNNEEDED CORRECT code, since string definitely cannot be null.
if (string != null && string.length() == 0)