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Difference between Inheritance and Composition
...r example :
class X implements R
{}
class Y implements R
{}
public class Test{
R r;
}
In Test class using r reference I can invoke methods of X class as well as Y class. This flexibility was never there in inheritance
3) Another great advantage : Unit testing
public class X {
p...
What is a 'semantic predicate' in ANTLR?
...ignore spaces
WhiteSpace
: (' ' | '\t' | '\r' | '\n') {skip();}
;
Testing
The grammar can be tested with the following class:
import org.antlr.runtime.*;
public class Main {
public static void main(String[] args) throws Exception {
ANTLRStringStream in = new ANTLRStringStream...
MySQL SELECT only not null values
...e for each column. That may possibly be avoided by the below but I haven't tested this in MySQL.
SELECT CASE idx
WHEN 1 THEN val1
WHEN 2 THEN val2
END AS val
FROM your_table
/*CROSS JOIN*/
JOIN (SELECT 1 AS idx
UNION ALL
...
PHP session lost after redirect
...use exit();)
Make sure cookies are enabled in the browser you are using to test it on.
Ensure register_globals is off, you can check this on the php.ini file and also using phpinfo(). Refer to this as to how to turn it off.
Make sure you didn't delete or empty the session
Make sure the key in your $...
How to check if an object is nullable?
... boxed, but you can with generics:
- so how about below. This is actually testing type T, but using the obj parameter purely for generic type inference (to make it easy to call) - it would work almost identically without the obj param, though.
static bool IsNullable<T>(T obj)
{
if (obj =...
varbinary to string on SQL Server
...20697320612074657374
select cast(@b as varchar(max)) /*Returns "This is a test"*/
This is the equivalent of using CONVERT with a style parameter of 0.
CONVERT(varchar(max), @b, 0)
Other style parameters are available with CONVERT for different requirements as noted in other answers.
...
Does Python have a string 'contains' substring method?
...class NoisyString(str):
def __contains__(self, other):
print(f'testing if "{other}" in "{self}"')
return super(NoisyString, self).__contains__(other)
ns = NoisyString('a string with a substring inside')
and now:
>>> 'substring' in ns
testing if "substring" in "a string...
How to best display in Terminal a MySQL SELECT returning too many fields?
...-+------------+-----------------+------------+------------+-
| % | test | | Y | Y | Y | Y | Y | Y | N | Y | Y | Y |
| % | test\_% | | Y | Y ...
Conditionally use 32/64 bit reference when building in Visual Studio
...ARCHITEW6432) returns AMD64 only on 64bit. Something to note if you try to test for x86 (because AMD64 is a derivative of x86 I assume).
– tjmoore
Jan 31 '13 at 12:47
...
How to redirect all HTTP requests to HTTPS
... link and deploys it to production that IS bad. It SHOULD be caught during testing, even with the redirection in place. I don't like the "could" argument because this "could" happen without the redirection in place. The symptoms are the same when testing in a secure browser, except after confirming...