PHP - string manipulation

PHP is a scripting language ideally suited for manipulating strings. That's why it is used for such activities as web scrapes, text manipulation, and text merges.

A string is any variable that is a literal value. In PHP, it is usually contained within quote marks. You can think of a string as just a lump of text.

Here’s an example of a string:

$string = "Let his Holiness Swami Baktanimbin relieve you of the heavy burden of your wallet. and the bad kharma of your credit card details.";

Printing this variable to the screen by writing the line

echo $string; would display:

Let his Holiness Swami Baktanimbin relieve you of the heavy burden of your wallet. and the bad kharma of your credit card details.

Now for some fun. PHP is feature rich with comands that assist in string manipulation. For example, if you wanted to capitalise every word in the above $string, all you need do is use the ucwords command

echo ucwords($string);

would give you

Let His Holiness Swami Baktanimbin Relieve You Of The Heavy Burden Of Your Wallet. And The Bad Kharma Of Your Credit Card Details

Perhaps you now want to capitalise every single letter. Using our original $string, all we need do is

echo strtoupper($string);
and we would get

LET HIS HOLINESS SWAMI BAKTANIMBIN RELIEVE YOU OF THE HEAVY BURDEN OF YOUR WALLET. AND THE BAD KHARMA OF YOUR CREDIT CARD DETAILS.

We can also go the other way. Changing every letter to lowwer case is achieved by

echo strtolower($string);

which gives

let his holiness swami baktanimbin relieve you of the heavy burden of your wallet. and the bad kharma of your credit card details.

PHP has the ability to do searcgh and replace functions on the fly. For example, say we had a bit of text which needs a particular word replaced by a number of words.

For example, our original $string, you will recall, outputs

Let his Holiness Swami Baktanimbin relieve you of the heavy burden of your wallet. and the bad kharma of your credit card details.

If we write

$newstring = str_replace("Baktanimbin", "Chanjindapokit Baktanimbin", $string );
echo $newstring;

We get

You'll notice the str_replace() function takes three parameters, the word to be replaced ("Baktanimbin") the word or words to replace it with ("Chanjindapokit Baktanimbin") and the string you want to manipulate - in this case the string called $string.

This is a great technique for web scraping. The function used is strstr() which returns the rest of the string after a particular character or group or characaters (sometimes called a substring) is encountered.

For example:

This can be very useful for extarcting text from a web site. If you look at Blueswami's Googlefight page, you can see how this is used to extract data from Google. The PHP code for this page is below.

$SearchForm .= '<form name="SearchForm" action="" method="post">';

$SearchForm .= '<b>Term 1:</b><input type="text" name="term1" class="text" value="'.$searchString1.'"><br><br>';

$SearchForm .= '<b>Term 2:</b><input type="text" name="term2" class="text" value="'.$searchString2.'"><br />';

$SearchForm .= "<br><input type='submit' name='submit' value='Googlefight it!'>";

$SearchForm .= '</form>';

if (!isset($_POST['submit'])) {

} else {

$strquote="'";

$strplus='+';

$strbr='<br>';

$strscored =" scored a total of ";

$strspace=" ";

$str0='http://www.google.com/search?&q=';

$str1=$strquote.$_POST['term1'].$strquote;

$str2=$strquote.$_POST['term2'].$strquote;

$strA4=$str0.$str1;

$strA5=$str0.$str2;

$str4=str_replace($strspace, "+", $strA4);

$str5=str_replace($strspace, "+", $strA5);

function GetPageData($pageurl)

{ return(file_get_contents($pageurl));

}

function GrabPage($pageurl)

{

$pageurl = GetPageData($pageurl);

$pagecontent = $pageurl;

return($pagecontent);

}

$term1 = GrabPage($str4);

$term2 = GrabPage($str5);

Function Trimit($term)

{

$cutterm = strstr($term, "</b> of about <b>");

$endbit = strstr($cutterm, "</b> for <b>");

$finalterm = str_replace($endbit, "", $cutterm);

$deletethis = array(",", "</b> of about <b>" );

$termfinal = str_replace($deletethis, "", $finalterm);

if ($termfinal==""){$termfinal="0";}

return ($termfinal);

}

$finalfirstterm= Trimit($term1);

$finalsecondterm = Trimit($term2);

if ($finalfirstterm > $finalsecondterm) {$decision = $str1; $loser = $str2;

$winnumber=$finalfirstterm; $losenumber=$finalsecondterm; }

if ($finalsecondterm > $finalfirstterm) {$decision = $str2; $loser = $str1;

$winnumber=$finalsecondterm; $losenumber=$finalfirstterm;

}

if ($winnumber==0){$winnumber=1;}

if ($losenumber==0) {$losenumber=1;}

$awidth=($losenumber*(300/$winnumber));

$lwidth=floor($awidth);

$xwidth=($winnumber/$losenumber)*100;

$ywidth= floor($xwidth)-100;

$endwombat=' wins by '.$ywidth.' per cent';

$head ='<h4><b>'.$str1.' versus '.$str2.'</b></h4><br>';

$head .="<div style="width:300px; height:10px; background-color:#FF0000"></div>".$decision."<br><br>";

$head .="<div style="width:".$lwidth."px; height:10px; background-color:#FF0000"></div>".$loser."<br>";

}

$wombat=$SearchForm.$head.$str1.$strscored.$finalfirstterm.$strbr.$str2.$strscored.$finalsecondterm.$strbr.'<b>'.$decision.$endwombat.'</b>';

return ($wombat);