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You have completed PHP Standards and Best Practices!
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In the olden days, PHP developers converted everything to unix timestamps before comparing dates, but now using DateTime you can just compare the objects directly.
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Now we know how to make a date time
object,
0:00
we should learn how to do things with
them.
0:02
One of the first things we might like to
do is compare dates.
0:03
Date comparisons are made very easy in
PHP.
0:07
Many older tutorials will suggest you have
to turn all dates into Unix time
0:10
stamps before you can compare the number
of seconds, but
0:13
date time objects can be compared
directly.
0:16
Try and steer clear of the old date, and
STR time functions.
0:19
And definitely avoid adding and
subtracting specific numbers of
0:22
seconds to change dates due to time zone
complications.
0:25
Let's take a look at time zones in the
next video.
0:29
Let's open the index.php file in our work
space now.
0:33
And have a look at another handy feature
of date time that is often under utilized.
0:35
On lines three and four, we are creating
two new date time objects,
0:39
both of which contain dates in their
supported format.
0:43
On line three, there is an object named
dvone.
0:46
And on line four contains an object named
spike.
0:48
These daytime objects represent the
birthdays of famous
0:51
WWE wrestlers D-Von Dudley and Spike
Dudley.
0:54
Below that on line eight is an if
statement.
0:57
This if statement is comparing which is
lesser out of the two objects.
0:59
At first it might seem odd to compare two
objects directly, but when this is used,
1:04
the internal values of the date,
regardless of the format they were
1:08
created with will be compared to see which
is the lesser of the two.
1:10
Think about it.
1:14
If somebody is born in 1900, then that is
a small number than 2000.
1:15
And somebody born in 1900 is certainly
older than someone born in 2000.
1:19
When we run this we should expect to see
the paragraph Spike is
1:23
older than D-Von output.
1:26
As Spike was born in 1970, almost two
years before D-Von.
1:28
Great our if statement worked, and we know
who is older.
1:34
Comparisons are useful, but
1:36
we can also look at the actual difference
between the two dates.
1:37
This will let us see what the age gap
really is.
1:40
So we go back to our workspace here.
1:42
Uncomment these lines.
1:45
Refresh that.
1:48
There we have it.
1:49
There is one year, 11 months, and 19 days
between Spike and D-Von.
1:50
But how do we do that.
1:54
On line 16, we are creating an object and
storing it in a variable called diff.
1:56
This object is an instance of date time
interval.
2:00
And that means we can call methods on it.
2:03
One method we recall is the format method.
2:05
This is a little different to the
DateTime Format method, but
2:07
it works in much the same way.
2:09
We can pass it as string and use certain
characters preceded by a percentage sign
2:10
to denote actual values that represent a
portion of the difference.
2:14
For example, we have a percent y, which
will show the number of years,
2:18
a percent m, which shows the number of
months.
2:22
And percent d, which you guessed it, shows
the number of days.
2:24
That's a good introduction to DateTime and
comparisons.
2:27
So, now we're gonna move on to time zones.
2:30
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