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Learning PHP (5) – Using built-in functions

June 12th, 2009 by admin | No Comments | Filed in Learning PHP

I had promised myself that I would post every second day, but I didn’t know exactly where to go from what we have built up and I also became engaged, she said yes! So it has been crazy days.
But I’m happy, at least :-D

I am going to continue with showing how to take use of some of the built-in string fuctions. These can be used to manipulate text variables that you might receive from the $_GET and $_POST variables.

Find occurrence of text in strings
You can for example use the function strstr() or stristr() if you want a cast-insensitive matching style.

Example

$mystring = 'this websites owner is nice';
if (strstr($mystring, 'website')) {
 echo 'I found the word "website" in the string.';
}

I can use double quotes in the string because I have it enclosed in single quotes.
If I were to use single quotes it would unquote the string and generate a syntax error.

If you replace strstr with stristr in the example, it would
also give a match if $mystring contains the word ‘Website’ with an upper case W.

explode() strings
If you get a string such as “one,two,three,four,five,six” and you would rather have
it indexed in an array you can use the function explode() to achieve this.

The build-in function explode() will parse a string and split it based on the
argument you give the function. An example will follow:

$mystring = "one,two,three,four;five,six,seven";
$myarray = explode(",", $mystring);

var_dump($myarray);

The first argument to explode is the delimiting character, while the other
is the string that will be split into an array. The result of this would be:

array(6) {
[0]=>
string(3) “one”
[1]=>
string(3) “two”
[2]=>
string(5) “three”
[3]=>
string(9) “four;five”
[4]=>
string(3) “six”
[5]=>
string(5) “seven”
}

Notice that $myarray[3] contains four;five, this is due to a common
mistake.. it can be hard to overlook, so can you figure out why it does that? :-D

Anyways, you should check out the documentation and try out some
of the functions, because they are really easy to use and implement.

Good luck!

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