Jeff, your code is nice but could be clearer with constants (as suggested in Code Complete).
const int SECOND = 1;
const int MINUTE = 60 * SECOND;
const int HOUR = 60 * MINUTE;
const int DAY = 24 * HOUR;
const int MONTH = 30 * DAY;
var ts = new TimeSpan(DateTime.UtcNow.Ticks - yourDate.Ticks);
double delta = Math.Abs(ts.TotalSeconds);
if (delta < 1 * MINUTE)
return ts.Seconds == 1 ? "one second ago" : ts.Seconds + " seconds ago";
if (delta < 2 * MINUTE)
return "a minute ago";
if (delta < 45 * MINUTE)
return ts.Minutes + " minutes ago";
if (delta < 90 * MINUTE)
return "an hour ago";
if (delta < 24 * HOUR)
return ts.Hours + " hours ago";
if (delta < 48 * HOUR)
return "yesterday";
if (delta < 30 * DAY)
return ts.Days + " days ago";
if (delta < 12 * MONTH)
{
int months = Convert.ToInt32(Math.Floor((double)ts.Days / 30));
return months <= 1 ? "one month ago" : months + " months ago";
}
else
{
int years = Convert.ToInt32(Math.Floor((double)ts.Days / 365));
return years <= 1 ? "one year ago" : years + " years ago";
}
Short Answer
Use $this
to refer to the current
object. Use self
to refer to the
current class. In other words, use
$this->member
for non-static members,
use self::$member
for static members.
Full Answer
Here is an example of correct usage of $this
and self
for non-static and static member variables:
<?php
class X {
private $non_static_member = 1;
private static $static_member = 2;
function __construct() {
echo $this->non_static_member . ' '
. self::$static_member;
}
}
new X();
?>
Here is an example of incorrect usage of $this
and self
for non-static and static member variables:
<?php
class X {
private $non_static_member = 1;
private static $static_member = 2;
function __construct() {
echo self::$non_static_member . ' '
. $this->static_member;
}
}
new X();
?>
Here is an example of polymorphism with $this
for member functions:
<?php
class X {
function foo() {
echo 'X::foo()';
}
function bar() {
$this->foo();
}
}
class Y extends X {
function foo() {
echo 'Y::foo()';
}
}
$x = new Y();
$x->bar();
?>
Here is an example of suppressing polymorphic behaviour by using self
for member functions:
<?php
class X {
function foo() {
echo 'X::foo()';
}
function bar() {
self::foo();
}
}
class Y extends X {
function foo() {
echo 'Y::foo()';
}
}
$x = new Y();
$x->bar();
?>
The idea is that $this->foo()
calls the foo()
member function of whatever is the exact type of the current object. If the object is of type X
, it thus calls X::foo()
. If the object is of type Y
, it calls Y::foo()
. But with self::foo(), X::foo()
is always called.
From http://www.phpbuilder.com/board/showthread.php?t=10354489:
By http://board.phpbuilder.com/member.php?145249-laserlight
Best Answer