Almost a year ago I wrote a quick article on how you can strip off characters using PHP’s built in function substr. But after reading it again, even I was not clear how it worked so how would it ever help anyone.

First, if you only want to pull on character from a string, it’s a lot easier to use the following:

$string = 'puppy';
echo $string[0]; // p
echo $string[1]; // u
echo $string[2]; // p ...and so on

Here’s the basic concept behind substr:
substr($string, start # [, length #]) - length is in brackets because it’s optional

Now let’s use this function to get a better idea of what it does.


$string = ‘categories’;
echo substr($string, 0); // ‘categories’ because we asked to start at the first character (which is 0 from the first example above) and goes right until end of string
echo substr($string, 3); // ‘egories’ because started at the third character in the string and went to the end
echo substr($string, -1); // ’s’ this is different from above because it starts at the end and goes left that number of characters
echo substr($string, -3); // ‘ies’



echo substr($string,3,4); // ‘egor’ - starts at the fourth character (remember 0 is the first) and shows 4 characters total (length)
echo substr($string,1,3); // ‘ate’ - starts at the second character and shows 3 characters total (length)
echo substr($string,1,-2); // ‘ategori’ because we started at the second character and also stripped off the last two with the “-2″
echo substr($string,-3,-2); // ‘i’ since we’re starting from the third character from the left and then are stripping off two characters from that with the “-2″


A practical use that I use quite often is if I only want to display a preview description rather than showing the whole large description.


$text = ‘Great for home, school or travel. Wonderful gift item!’;
echo substr($text, 25).’…’; // displays “Great for home, school or…”


There are other very practical reasons to use substr. Please leave a comment if you have one of your own that you think would be beneficial to share.