Changing Case in PHP
The ability take strings of text and manipulate them is one of the
essential abilities you need as a programmer. If a user enters details
on your forms, then you need to check and validate this data. For the
most part, this will involve doing things to text. Examples are: converting
letters to uppercase or lowercase, checking an email address to see
if all the parts are there, checking which browser the user has, trimming
white space from around text entered in a text box. All of these come
under the heading of string manipulation. To make a start, we'll look
at changing the case of character.
Changing the Case of a Character
Suppose a you have a textbox on a form that asks users to enter a first
name and surname. The chances are high that someone will enter this:
bill gates
Instead of this:
Bill Gates
So your job as a programmer is to convert the first letter of each
name from lower to uppercase. This is quite easy, with PHP.
There's a script amongst the files you
downloaded called changeCase.php. Open up this page to see
the code.
It's just a textbox and a button. The textbox will already have "bill
gates" entered, when you load it up. What we want to do is to change
it to "Bill Gates" when the button is clicked. Here's the
script that does that.
<?PHP
$full_name = 'bill gates';
if (isset($_POST['Submit1'])) {
$full_name = $_POST['username'];
$full_name = ucwords($full_name);
}
?>
The first line just makes sure that the lowercase version is placed
into the textbox when the page loads:
$full_name = 'bill gates';
This is the line that we want to convert and turn in to "Bill
Gates". The only line in the code that you haven't yet met is this
one:
$full_name = ucwords($full_name);
And that's all you need to convert the first letter of every word to
uppercase! The inbuilt function is this:
ucwords( )
In between the round brackets, you type the variable or text you want
to convert. PHP will take care of the rest. When the conversion is complete,
we're storing it back into the variable called $full_name.
If you just want to convert the first letter of a string (for a sentence,
for example), then you can use ucfirst( ) . Like this:
$full_ sentence = ucfirst($full_
sentence);
To convert all the letters to either upper or lowercase, use these:
strtoupper( )
strtolower( )
Here's an example of how to use them:
$change_to_lowercase = "CHANGE THIS";
$change_to_lowercase = strtolower($change_to_lowercase);
$change_to_uppercase = "change this";
$change_to_uppercase = strtoupper($change_to_lowercase);
Again, the variable or text you want to change goes between the round
brackets of the function. This is then assigned to a variable.
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