PHP Logical Operators

Logical Operators

Example	Name	Result
$a and $b	And	TRUE if both $a and $b are TRUE.
$a or $b	Or	TRUE if either $a or $b is TRUE.
$a xor $b	Xor	TRUE if either $a or $b is TRUE, but not both.
! $a	Not	TRUE if $a is not TRUE.
$a && $b	And	TRUE if both $a and $b are TRUE.
$a || $b	Or	TRUE if either $a or $b is TRUE.

php regular expresion

<?

$line = "Vi is the greatest word processor ever created!";
// perform a case-Insensitive search for the word "Vi"
if (preg_match("/\bVi\b/i", $line, $match)) :
  print "Match found!";
endif;


echo "<br>";


if (preg_match("/\bweb\b/i", "PHP is the web scripting language of choice.")) {
    echo "A match was found.";
} else {
    echo "A match was not found.";
}

?>

Imprimiendo comilla doble en PHP

<?
echo  " asterisk -x \" sip show peers \"";

?>

Solo tenemos que poner un  \ delante de la comilla  ejemplo    <?php echo " \"hola"; ?>

imprime  "hola

Y esto   <?php   echo " \"hola\"";  ?>

"hola"
  

PHP Assignment by Reference

Assignment by Reference ¶

Assignment by reference is also supported, using the "$var = &$othervar;" syntax. Assignment by reference means that both variables end up pointing at the same data, and nothing is copied anywhere.

Example #1 Assigning by reference

<?php
$a = 3;$b = &$a; // $b is a reference to $a
print "$a\n"; // prints 3print "$b\n"; // prints 3
$a = 4; // change $a
print "$a\n"; // prints 4print "$b\n"; // prints 4 as well, since $b is a reference to $a, which has
              // been changed?>

 

 

Esto es comoa acceso directo a  una variable 

Agregando valores automaticos a un arreglo he interactuando sobre ellos

<?php
$peers=array();

$peers[]=a;
$peers[]=b;
$peers[]=c;
$peers[]=d;


foreach ($peers as $extensions) {

echo $extensions."<br>";

$peers++;

}

?>

a
b
c
d

return devuelve el valor de una variable x llamada dentro de una funcion, y transforma la  funcion misma en una variable misma igual  al valor de la variable x ya mencionada con el return


ejemplo $a sera igual al valor de la suma de $var+$var1 y la funcion sum( $var,$var1) sera igual al valor de $a. Por ende podemos usar esta funcion como si fuese una variable


 <?
function sum($var,$var1){

$a=$var+$var1;

return $a;


}

 if(sum(10,10)==20){


 echo " function  value is 20";
}

else {

echo " function  value is  not  equal to 20";

}

?>

function  value is 20

using-linux-awk-command-in-php

$output = exec('awk -v OFS=, \'/hello/i {$1=$1;print}\' test.txt > newtest.txt');

http://stackoverflow.com/questions/16419070/using-linux-awk-command-in-php