Functions

[liteon]

As a newbie, I tried to create a function.

The function should read a content of an already used variable (e.g. $t=’’😉 and if it has nothing inside it should assign 0 instead.

I wrote it like this but it does not work, why?

<?php
$t='';
function aszero($var)
{
trim($var);
if ($var=='')
{
$var=0;
}
}
aszero($t);
echo($t);
?>

[barand]

function aszero($var)
{
trim($var);
if ($var=='')
{
$var=0;
}
}

$var in your function is 'local' to that function and not available outside it.

There are three ways of doing what you want to do

1. Safest - return a value from the function

2. Pass the variable $t by reference - the default is by value

3. Least safe - declare $t as global within the function
   [/list=1]

   These three sets of code will do the trick

   function aszero1($var) 
   { 
      trim($var); 
      if ($var=='') 
      { 
         $var=0; 
      } 
      return $var;
   } 
   
   $t = '';
   $t = aszero1($t);
   
   /*******************/
   
   function aszero2(&$var) 
   { 
      trim($var); 
      if ($var=='') 
      { 
         $var=0; 
      } 
   
   } 
   
   $t = '';
   aszero2($t);
   
   /********************/
   function aszero3() 
   { 
      global $t;
      trim($t); 
      if ($t=='') 
      { 
         $t=0; 
      } 
   } 
   
   $t = '';
   aszero3();
   

   hth