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List ALL kinds of symbols in PHP (awesomely comprehensive!!)

Setting variable:
if (!isset($myvar)) $myvar = 'joe'; and other ways

Creating an associative array: $massiiv[] = array();

++$i   pre-increment
$i++   post-increment

echo nl2br ("some \n text")   linebreak in echo

& before a variable/argument as in someFunction(&$argument) is a reference to the original (not copy)(any manipulation of the variable will affect the original)

function foo(&$bar) {
  $bar = 1;
}
$x = 0;
foo($x);

echo $x;    //returns 1

$_SERVER['HTTP_HOST'].$_SERVER['SCRIPT_NAME'] should show the complete path

(int) in front of a variable tries to convert it to an integer   eg echo (int) $var

foreach($responsibilities as $i => $resp) { 
  $resp = preg_replace(
        $patterns = array('/^(\d\.\s(?!aastane)|(\*)+\s*|\t|-|\s*)|\s$/', '/(?<!:|\.)\s*$/'),   
        $replace  = array('','.'), 
        $resp
    );  
    
    //is the same as 
    $resp = preg_replace('/^(\d\.\s(?!aastane)|(\*)+\s*|\t|-|\s*)|\s$/','',$resp);
    //and
    $resp = preg_replace('/(?<!:|\.)\s*$/','.',$resp);
}

Operators

Boolean operator || returns boolean value
If an operand evaluates to false, subsequent operands are skipped, eg false && foo() never gets to foo()

Binary (bitwise) operator | returns numerical or alphabetic value
Operand is converted into and evaluated in binary system but returned in decimal
All operands are checked, eg false & foo() also evaluates foo()

1. convert all operands into binary (see ASCII table for words)
2. compare binaries (get true-false value)
3. convert resulting binary back into decimal (numbers/letters)

14 & 7   /*returns 6*/              7 | 25 & 8   /*returns 15*/
  
                                       7 = 00111
  14 = 1110                           25 = 11001
  7  = 0111                            8 = 01000
  ---------                            ----------
       0110 = 6 in dec                      (01000)  25 & 8
                                             01111 = 15 in dec

for words:

"tere" | "tee"   /*returns tewe*/                           "tere" & "tee"   /*returns  te` */

tere      01110100 01100101 01110010 01100101               01110100 01100101 01110010 01100101
tee       01110100 01100101 01100101 00100000 for space     01110100 01100101 01100101 00100000
          -----------------------------------               -----------------------------------
TF value  01110100 01100101 01110111 01100101 = tewe        01110100 01100101 01100000 00100000

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