This is really strange...

Question

Hi, has anybody here ever encountered such problem?
My code is like:
String date = Util.Bytes2String(m_sDate);     
if (date!="")
try{
String yy = date.substring(0, 4);      
String mm = date.substring(4, 6);
} catch (Exception e){}
I have tested that the string date is empty(="") but the "try" statement is still executed, why? This is really strange to me.
Thank you.

Answer 1

Use
if (!("".equals(date)))You only use == and != to
1) compare primitives
2) see if a reference is null
3) see if two references refer to the same object
Even if date contains the empty String, it doesn't necessarily (and in your code won't) refer to the same object as the one in the constant pool that holds your "" String object.