Tag Archives: PHP

Arrays certainly are useful. If you’re dealing with associative data, there’s no better tool for the job. Sometimes, you’ll run into cases where it would be useful to store an entire array in a field in a database. It’s not something you want to do if you can avoid it, by structuring your database’s tables more efficiently for example, but there are cases where it’s unavoidable.

That’s where serialize() comes in. You can pass an array to the function, and it will return a string that is essentially the array flattened and mashed down. You can then unserialize() it to obtain the full array once again.

<?php
$the_array = array( "Lorem", "Ipsum", "Dolor" );
$serialized = serialize($the_array);
print $serialized;
?>

This will output a:3:{i:0;s:5:"Lorem";i:1;s:5:"Ipsum";i:2;s:5:"Dolor";}. It’s the whole array in string form, suitable for insertion into a database field. It will work with more complex arrays, of course, but simple is better for examples.

Have you ever wanted to take a string and replace every occurance of a substring with something else? Regular Expression voodoo is what first comes to mind for a lot of PHP developers. But there is an easier way that just happens to be faster.

Str_Replace() accepts up to four parameters, three of which are required. The first is the substring to look for, the second is the substring to replace it with, and the third is the input string. (The optional fourth parameter is used to set a maximum amount or times to run the replace operation.) The function returns the new string.

You’re not limited to replacing a single substring either. You can pass arrays for the search and replace parameters.

Continue reading →

Explode() is a widely-used PHP string function that is also one that tends to mystify beginners looking at others’ code. It’s a nifty little function that you may find plenty of uses for once you know how it works.

Explode() takes two arguments, a delimiter and the string you wish to operate on, then returns an array. The function splits a string into multiple pieces at the delimiter, and puts each piece into a numerical array.

Have a list of comma-separated words? (A scenario increasingly common now that “tagging” has become such a popular device.) You can pass a comma-delimited string to explode() with a delimiter of “,” and voila, you have an array containing each of the items.

$string = "lorem, ipsum, dolor";
$delimiter = ", ";
$array = explode($delimiter, $string);

Now you have a single-dimension numerical array with each list item in it. $array[0] would contain “lorem” and $array[1] would be “ipsum” and so on.

Continue reading →

I was trawling through the PHP function reference the other day, looking for some information on regular expressions, when I happened across this gem:

$text = ereg_replace("[[:alpha:]]+://[^<>[:space:]]+[[:alnum:]/]", "<a href=\"\\0\" rel=\"nofollow\">\\0</a>", $text);

It may look like gibberish at first, but if you look at it for awhile, you might be able to guess what it does.

Suppose you’re writing a PHP script that displays data, let’s use blog comments as an example. Sometimes the data being displayed may have a URL pasted into it by the user that submitted it. Wouldn’t it be nicer for the end user if URLs like that were automatically turned into clickable links, so “http://google.com” would become “http://google.com?”

That’s exactly what this line of PHP code does. It takes the variable $text and parses through it, converting stray URLs into clickable links.