The ability to manipulate string
variables in PHP is extremely
helpful. This tutorial will
outline some of the more common
situations you’ll encounter
when working with PHP string
variables.
Review: what’s a string?
In PHP, and every other flavor
of Web programming, a string
is a variable contained between
quotes with a literal value.
For example, $number = “2” is
a string variable, whereas $number
= 2 is not. The first value
is seen as text only, the latter
as a numeric value. Simply put,
a string is a text variable.
Working with PHP strings: setting
the stage
For this tutorial, we need a
string variable to work with.
Since my Red Sox were promptly
ousted in last night’s MLB Playoffs,
we’ll use them as my whipping
boy. Here’s our string:
<?php
$string = "The Boston Red
Sox lost because of poor pitching,
bad defense, and a lack of offense.
That doesn’t leave much, does
it?";
?>
If we printed this variable
(echo $string;) it would display:
The Boston Red Sox lost because
of poor pitching, bad defense,
and a lack of offense. That
doesn’t leave much, does it?
Capitalize the first letter
of every word in a PHP string
Let’s say we have a situation
where we’re pulling information
out of a database (maybe book
titles or first names and last
names) and we want to make sure
the first letter of each word
is capitalized. This is easily
accomplished with the function
ucwords().
<?php
$string ="The Boston Red
Sox lost because of poor pitching,
bad defense, and a lack of offense.
That doesn’t leave much, does
it?";
echo ucwords($string);
?>
This would print:
The Boston Red Sox Lost Because
Of Poor Pitching, Bad Defense,
And A Lack Of Offense. That
Doesn’t Leave Much, Does It?
Capitalize every letter in a
PHP string
<?php
$string = "The Boston Red
Sox lost because of poor pitching,
bad defense, and a lack of offense.
That doesn’t leave much, does
it?";
echo strtoupper($string);
?>
Prints:
THE BOSTON RED SOX LOST BECAUSE
OF POOR PITCHING, BAD DEFENSE,
AND LACK OF OFFENSE. THAT DOESN’T
LEAVE MUCH, DOES IT?
Make every letter in a PHP string
lowercase
Very similar to the above example,
except we use the PHP function strtolower() instead
of strtoupper().
<?php
$string = "The Boston Red
Sox lost because of poor pitching,
bad defense, and a lack of offense.
That doesn’t leave much, does
it?";
echo strtolower($string);
?>
Prints:
the boston red sox lost because
of poor pitching, bad defense,
and lack of offense. that doesn’t
leave much, does it?
Replace parts of a PHP string
We can also replace part of
our string with an entirely
different piece of text. Consider
it PHP’s built in “Find and
Replace” function. This is accomplished
via the str_replace() function.
<?php
$string = "The Boston Red
Sox lost because of poor pitching,
bad defense, and a lack of offense.
That doesn’t leave much, does
it?";
$newstring = str_replace("Boston
Red Sox", "New York
Yankees", $string );
echo $newstring;
?>
The str_replace() function
takes 3 parameters. In my example,
I used “Boston Red Sox,” “New
York Yankees”, and $string.
The first parameter is the piece
of text you want to replace.
The second is the text that
will replace the original. The
third parameter tells PHP what
value to do the find and replace
on (in this case, my original
$string variable).
In the above example, echo
$newstring will print:
The New York Yankees lost because
of poor pitching, bad defense,
and a lack of offense. That
doesn’t leave much, does it?
After Randy Johnson’s stellar
pitching performance last night,
it turns out this might actually
be true before the end of the
weekend. Red Sox and Yankee
fans unite!
Return all data AFTER a given
character/string
This is a tricky technique.
By using the PHP function strstr() I
can return every part of the
string after a given character
or characters that I specify.
For example:
<?php
$string = "The Boston Red
Sox lost because of poor pitching,
bad defense, and a lack of offense.
That doesn’t leave much, does
it?";
$newstring =strstr ($string,
"Boston");
echo($newstring);
?>
I passed the strstr() function
2 parameters. The first is what
variable to perform the string
manipulation on($string).
The second is the cutoff point
in the text (take everything
after and including this point).
The output of $newstring would
be:
Boston Red Sox lost because
of poor pitching, bad defense,
and a lack of offense. That
doesn’t leave much, does it?
I could also do:
$newstring =strstr ($string,
"That");
Which would display:
That doesn’t leave much, does
it?
Advanced: Return all data BEFORE
a given character/string
I can also print all of the
data that occurs before a certain
character or string component
occurs. This is an advanced
technique that requires 2 functions: substr() and strpos().
Currently, my $string variable
consists of two sentences. By
using a clever combination of
substr() and $strpos, I can
cut off the entire second sentence,
leaving me with only the first.
<?php
$string = "The Boston Red
Sox lost because of poor pitching,
bad defense, and a lack of offense.
That doesn’t leave much, does
it?";
$newstring = substr($string,
0, strpos($string, "."));
echo($newstring);
?>
This would print:
The Boston Red Sox lost because
of poor pitching, bad defense,
and a lack of offense
