[Adding class to links and finding links]

change $pattern2 to

$pattern2 = '/(<a [^>]*href=([\'"])'. $url . '\2)([^>]*)/is';

[Building strings]

for($i= 'a'; $i <'zz'; $i++) echo $i;

not tested

[PHP Letter Sequence Generator]

or

<?php
$ltrs = "ABCDEFGHJKLMPQRS";
$ltrs = str_split($ltrs);
shuffle($ltrs);
for($i=0; $i<3; $i+=2) $str .= $ltrs[$i]<$ltrs[$i+1] ? $ltrs[$i].$ltrs[$i+1] : $ltrs[$i+1].$ltrs[$i];
echo $str;
?>

[Adding class to links and finding links]

1.

<?php
$class_name = 'my_class';
$html = '<a id="23" href="sa\'sa.com" class="yyy" bla bla>xx</a>';
$pattern1 = '/(<a [^>]*) class=([\'"])[^\2]+\2([^>]*>)/is';
$replace1 = '\1\3';
$pattern2 = '/(<a [^>]*href=([\'"])[^\2]+\2)([^>]*)/is';
$replace2 = '\1 class="'. $class_name .'"\3';

$html = preg_replace($pattern1, $replace1, $html);
echo $html = preg_replace($pattern2, $replace2, $html);
?>

[regexp replace part of pattern problem]

try

$pattern = '@(body[^\{\}]*?\{[^\{\}]*?background:)#([0-9A-F]{6})(;[^\{\}]*?\})@s';
echo $new_str_1 = preg_replace($pattern,"$1#".$newcolor."$3",$str);

in your example replace string is "$11A2B3C$3"

start of it $11 means 11th subpatern that not exist

i remove # from 1st subpatern and add it literaly

[Search Problem in array]

try

<?php
$test = Array (
0 => Array ( 'row_color' => 'sectiontableentry1',
    'product_name' => 'Standaard Roll-up banner - 85 x 205 cm Standaard: Roll-up banner (= €117,81)',
    'product_attributes' => '',
    'product_sku' => '00001',
    'product_availability' => '',
    'product_price' => '€117,81',
    'quantity' => 1,
    'subtotal' => '€117,81',
    'update_form' => '',
    'delete_form' => ''),
1 => Array ( 'row_color' => 'sectiontableentry2',
    'product_name' => 'Test2 Losse: spandoek_UV-Print',
    'product_attributes' =>'',
    'product_sku' => '10001',
    'product_availability' =>'',
    'product_price' => '€258,83',
    'quantity' => 1,
    'subtotal' => '€258,83',
    'update_form' =>'',
    'delete_form' =>''),
2 => Array ( 'row_color' => 'sectiontableentry1',
    'product_name' => 'Luxe Roll-up banner - 85 x 205 cm Luxe: Roll-up banner (= €213,01)',
    'product_attributes' =>'',
    'product_sku' => '00002',
    'product_availability' =>'',
    'product_price' => '€213,01',
    'quantity' => 1,
    'subtotal' => '€213,01',
    'update_form' => '',
    'delete_form' => ''));
function my_find_in_sku($array, $srch){
    foreach ($array as $v) if($v['product_sku'] == $srch) return true;
    return false;
}
if(my_find_in_sku($test, '10001')){
    echo 'find it';
} else {
    echo 'not';
}

?>

[Regular Expression Question]

<?php
$page ="<input type=\"hidden\" autocomplete=\"off\" name=\"xhpc_composerid\" value=\"u269995_3\" \/>";
preg_match('|<input\s[^>]*name="xhpc_composerid"\s[^>]*value="([^"]*)"[^>]*>|', $page, $match);
print_r($match);
?>

[Averaging]

try

<?php
        // connect to the database
        $dbLink = mysql_connect("Blah",
                                "Blah",
                                "blah");
        if (!$dbLink) {
                print "Could not connect: ".mysql_error();
                exit(0);
        }

        if (!mysql_select_db("answerchoice", $dbLink)) {
                print "Could not select database: ".mysql_error();
                exit(0);
        }

$query= "SELECT AID FROM answer WHERE (QID = 18) AND UID IN (SELECT UID FROM answer WHERE Answer = 33) ORDER BY AID ASC";
$result = mysql_query($query, $dbLink);
//this query returns data base answer choice numbers (commas added by me for readability) 52,52,52,52,52,52,52,52,54,54,55,55,55,56,56,56
$i = 0;
$tmp = -1;
$ans = array();
while($row = mysql_fetch_array($result)){
    if($row['AID'] > $tmp){
        $i++;
        $tmp = $row['AID'];
        $ans[$i]=0;
    }
   $ans[$i]++;
//$i now holds the answer numbers converted into a 1-4 value (commas added by me for readability)1,1,1,1,1,1,1,1,2,2,3,3,3,4,4,4 I would like to average this string which would be 2.0265
}
foreach ($ans as $v => $c){
    $tot += $v * $c;
    $cnt += $c;
}
if($cnt ) $ave = $tot / $cnt; else $ave = 0;
echo 'average = ',$ave;
?>

[Unexpected T-STRING!!]

you have same fun qoutes in the begin of string

change “ to "

[Processing Problem Related to "Hardened" PHP Environment]

change  $GET to$_GET in line 469

[can't figure out why this not working]

remove  single qvotes around the filename in your query

$transfer = mysql_query("UPDATE  members SET balance = '$newblanceto' WHERE bankaccount='$to_acct'") or die ("could not write to profile");

[Array instead of value]

use implode() function

[Insert labels of checked checkboxes in database]

<?php
$i = 1;
foreach ($_POST['chk_b'] as $index => $option) 
{
echo $option, '<br>';
        $fields[$i] = "`EXP$i`";
$value[$i] = "'$option'";
$i++;
}
//echo
$sql = "INSERT INTO table_name (". implode(', ', $fields). ") VALUES (". implode(', ', $value). ")";
?>

[Insert labels of checked checkboxes in database]

change chkbox name and add value attribute

$tmp[] = '<li id="li'  . $i . 'b"><label for="chk' . $i . 'b"><input name="chk_b[' . $i . ']" id="chk' . $i . 'b" type="checkbox" value ="'.$option.'"onchange="Enable(\'chk' . $i . 'b\',\'li' . $i . 'b\')">' . $option . '</label></li>';

and on submit page do

foreach $_POST['chk_b'] as $index => $option) echo $index, ' -> ', $option, '<br />\n';

[Lucas–Lehmer Primality Test]

number $s is overflow integers (try to echo it)

to fix it use modulo operator in calculating $s

<?php

for ($i = 2; $i < 10; $i++) { // testing from (2^2 - 1) to (2^10 - 1)
    $s = 4;
    $m = pow(2, $i) - 1; // define M
    if ($i > 2) { // Start computing $s only if ($i - 2) > 0, otherwise $s remains equal to 4.
        for ($j = 1; $j <= $i - 2; $j++) { // Find S(p-2)
            $s = (($s * $s) - 2) % $m;
        }
    }
    if ($s == 0) {
        echo "<br />$m";
    } // Print out detected prime number.
}
?>

[Pulling out Phone Number and Email Addresses from an email message]

for e-mail

$pattern = '/From:.*?([A-Za-z0-9!#$%&\'*+-\/=?^_`{|}~\.]+@[A-Za-z0-9!#$%&\'*+-\/=?^_`{|}~\.]+)/';

[Add value to a variable without forming it before]

add space after +1

change +1. to +1 .

[Retrieving form values from multi dimensional array]

$_GET['submit'] is nut array

try

        print_r ($_GET); // test display form values
       
foreach ($_GET as $key => $value) {
	echo '<br/>'.$key.'<br/>	';
                     if($key != 'submit'){
	foreach ($value as $iKey => $iValue) { // Line 72
		foreach ($iValue as $xKey => $xValue) {
			echo " The $xKey for Player $iValue is $xValue <br/>";
		}
	}
                    }
}

[$_GET array?]

change

echo "<input type='checkbox' name='option".$i."' value='$objectname' checked>".$objectname;

to

echo "<input type='checkbox' name='option[".$i."]' value='$objectname' checked='checked'>".$objectname;

and in $_GET['option'] is array of checked object

[Binomial Distribution - How do I begin this?]

i wrote just pseudo code in pascal notation

php code looks like

$trials = 2; // Number of trials
$upgradeChance = 0.5; // Original percent rate of success 50%
$rateSuccess = 0;  // Total rate of success is 3 of 4

$rateSuccess = 1 - pow((1 - $upgradeChance), $trials) ;
echo "Chance of Success: <b>".$rateSuccess * 100 ."%</b><br>";

[help in preg match]

try to use mysql function STR_TO_DATE()

http://dev.mysql.com/doc/refman/5.0/en/date-and-time-functions.html#function_str-to-date

[Binomial Distribution - How do I begin this?]

chance_for_n_tries = 1 - (1 - chance)^n

 

for example chance is

1-(1-0.0096)^100

[unexpected $end]

your query is wrong

try something like

$query = "SELECT * FROM users WHERE username = '$user_username' AND `password` = '$user_password'";

[Need help making this work please]

<?
if ($_SESSION['memberid']!= 1000) include("themes/".$setts['default_theme']."/includes/side_nav/inc_side_nav_members_menu_tree.php"); 
?>
<? if ($_SESSION['memberid']== 1000) { ?>
<?
include("themes/".$setts['default_theme']."/includes/side_nav/inc_side_nav_members_menu_tree2.php"); 
?>

[Matching heights debug]

you must escape . (dot) too

/^[1-9]?((\.|,|\'|\s)([0-9]{1,2}))$/