23 dicembre 2014

Calendario 2015 verticale in excel, jpeg o pdf

Di seguito il link al calendario 2015: excel, jpeg e pdf

15 dicembre 2014

How compare strings in Java (in-depth examination)

There are two ways:
  • == tests for reference equality
  • .equals() tests for value equality


When using == operator for string comparison you are not comparing the contents of the string but are actually comparing the memory address, if they are both equal it will return true and false otherwise. 

Whereas equals in string compares the string contents.

Some examples:
// These two have the same value
new String("test").equals("test") // --> true 

// ... but they are not the same object
new String("test") == "test" // --> false 

// ... neither are these
new String("test") == new String("test") // --> false 

// ... but these are because literals are interned by 
// the compiler and thus refer to the same object
"test" == "test" // --> true 

// concatenation of string literals happens at compile time,
// also resulting in the same object
"test" == "te" + "st" // --> true

// but .substring() is invoked at runtime, generating distinct objects
"test" == "!test".substring(1) // --> false

// interned strings can also be recalled by calling .intern()
"test" == "!test".substring(1).intern() // --> true

How create a temporary table with a select in MySQL

I take note of this simple sintax:

CREATE TEMPORARY TABLE IF NOT EXISTS temp_table 

( INDEX(col_2) ) ENGINE=MyISAM 

AS ( SELECT col_1, coll_2, coll_3 FROM mytable )

Bye

3 gennaio 2014

How-to: remove "Download Complete" notice after upgrade Android 4.3

Solution
Go to "Settings" -> "Apps" -> "All" tab, select "Downloads" app and remove what it constantly notify after the upgrade.

Bye