php - string
explode
The PHP function explode lets
you take a string and blow it up into smaller pieces. For example, if you had a
sentence you could ask explode to use the sentence's spaces
" " as dynamite and it would blow up the sentence into separate
words, which would be stored in an array. The sentence "Hello, I
would like to lose weight." would look like this after explode
got done with it:
1.
Hello,
2.
I
3.
would
4.
like
5.
to
6.
lose
7.
weight.
The dynamite (the space character)
disappears, but the other stuff remains, but in pieces. With that abstract
picture of the explode function in mind, lets take a look at
how it really works.
he explode function
The first argument that explode takes is the delimiter (our dynamite)
which is used to blow up the second argument, the original string. explode returns an array of string pieces from
the original and they are numbered in order, starting from 0. Lets take a phone
number in the form ###-###-#### and use a hyphen "-" as our dynamite
to split the string into three separate chunks.
PHP Code:
$rawPhoneNumber = "800-555-5555";
$phoneChunks = explode("-", $rawPhoneNumber);
echo "Raw Phone Number = $rawPhoneNumber <br />";
echo "First chunk = $phoneChunks[0]<br />";
echo "Second chunk = $phoneChunks[1]<br />";
echo "Third Chunk chunk = $phoneChunks[2]";
If you want to control the amount of destruction that explode can
wreak on your original string, consider using the third (optional) argument
which allows you to set the number of pieces explode can return. This means it
will stop exploding once the number of pieces equals the set limit. Below we've
blown up a sentence with no limit and then with a limit of 4.
PHP Code:
$someWords =
"Please don't blow me to pieces.";
$wordChunks =
explode(" ", $someWords);
for($i = 0; $i
< count($wordChunks); $i++){
echo "Piece $i =
$wordChunks[$i] <br />";
}
$wordChunksLimited
= explode(" ", $someWords, 4);
for($i = 0; $i
< count($wordChunksLimited); $i++){
echo "Limited Piece $i =
$wordChunksLimited[$i] <br />";
}
The PHP function implode operates
on an array and is known as the "undo" function of explode.
If you have used explode to break up a string into chunks or
just have an array of stuff you can use implode to put them
all into one string.
php implode - repairing the damage
The first argument of implode is the string of characters you want
to use to join the array pieces together. The second argument is the array
(pieces).
PHP Code:
$pieces =
array("Hello", "World,", "I", "am",
"Here!");
$gluedTogetherSpaces
= implode(" ", $pieces);
$gluedTogetherDashes
= implode("-", $pieces);
for($i = 0; $i
< count($pieces); $i++){
echo "Piece #$i =
$pieces[$i] <br />";
}
echo
"Glued with Spaces = $gluedTogetherSpaces <br
/>";
echo
"Glued with Dashes = $gluedTogetherDashes";
While PHP's date() function
may seem to have an overwhelming amount of options available, isn't it always
better to have more choices than not enough? With PHP's date function you
format timestamps, so they are more human readable.
This lesson will teach you how to
display the current time, formating PHP's timestamp, and show you all the various
date arguments for reference purposes.
php date - the
timestamp
The date function always formats a
timestamp, whether you supply one or not. What's a timestamp? Good question!
- Timestamp: A timestamp is the number of seconds from January 1, 1970 at 00:00. Otherwise known as the Unix Timestamp, this measurement is a widely used standard that PHP has chosen to utilize.
The date function uses letters of the alphabet to represent
various parts of a typical date and time format. The letters we will be using in
our first example are:
- d: The day of the month. The type of output you can expect is 01 through 31.
- m: The current month, as a number. You can expect 01 through 12.
- y: The current year in two digits ##. You can expect 00 through 99
We'll tell you the rest of the options later, but for now let's
use those above letters to format a simple date! The letters that PHP uses to
represent parts of date and time will automatically be converted by PHP.
However, other characters like a slash "/" can be
inserted between the letters to add additional formatting. We have opted to use
the slash in our example.
PHP Code:
<?php
echo date("m/d/y");
?>
supplying a timestamp
As our first example shows, the first argument of the date function tells PHP how you would like
your date and time displayed. The second argument allows for a timestamp and is
optional.
This example uses the mktime function to create a timestamp for
tomorrow. To go one day in the future we simply add one to the day argument of mktime. For your future
reference, we have the arguments of mktime.
Note: These arguments are all optional. If you do not supply any
arguments the current time will be used to create the timestamp.
- mktime(hour, minute, second, month, day, year, daylight savings time)
PHP Code:
<?php
$tomorrow = mktime(0, 0, 0,
date("m"), date("d")+1, date("y"));
echo "Tomorrow is
".date("m/d/y", $tomorrow);
?>
If we were to run our new script just after the 2010 Winter
Olympics our display would look like:
php date - reference
Now that you know the basics of using
PHP's date function, you can easily plug in any of the
following letters to format your timestamp to meet your needs.
Important Full Date and Time:
- r: Displays the full date, time and timezone offset. It is equivalent to manually entering date("D, d M Y H:i:s O")
Time:
- a: am or pm depending on the time
- A: AM or PM depending on the time
- g: Hour without leading zeroes. Values are 1 through 12.
- G: Hour in 24-hour format without leading zeroes. Values are 0 through 23.
- h: Hour with leading zeroes. Values 01 through 12.
- H: Hour in 24-hour format with leading zeroes. Values 00 through 23.
- i: Minute with leading zeroes. Values 00 through 59.
- s: Seconds with leading zeroes. Values 00 through 59.
Day:
- d: Day of the month with leading zeroes. Values are 01 through 31.
- j: Day of the month without leading zeroes. Values 1 through 31
- D: Day of the week abbreviations. Sun through Sat
- l: Day of the week. Values Sunday through Saturday
- w: Day of the week without leading zeroes. Values 0 through 6.
- z: Day of the year without leading zeroes. Values 0 through 365.
Month:
- m: Month number with leading zeroes. Values 01 through 12
- n: Month number without leading zeroes. Values 1 through 12
- M: Abbreviation for the month. Values Jan through Dec
- F: Normal month representation. Values January through December.
- t: The number of days in the month. Values 28 through 31.
Year:
- L: 1 if it's a leap year and 0 if it isn't.
- Y: A four digit year format
- y: A two digit year format. Values 00 through 99.
Other Formatting:
- U: The number of seconds since the Unix Epoch (January 1, 1970)
- O: This represents the Timezone offset, which is the difference from Greenwich Meridian Time (GMT). 100 = 1 hour, -600 = -6 hours
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