PHP - Call a function with no return that does actually change values -

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• changing global variable inside function php 4 answers

i want call function in php, changes existing variables without returning specific one.

here example:

<?php   $number1 = 5;   $number2 = 3;   echo $number1;   echo $number2; //shows unmodified numbers    modifynumbers($number1, $number2); // modifies numbers    echo $number1;   echo $number2; //shows modified numbers ?>  <!-- stuff -->  <?php   function modifynumbers($number1, $number2) {     /* doing math stuff numbers */     /* no return because many numbers changed / overwritten   } ?> 

basically, want make function overwriting variables instead of giving specific value specific variable function called.

thanks in advance!

pass reference &

<?php   $number1 = 5;   $number2 = 3;   echo $number1;   echo $number2; //shows unmodified numbers    modifynumbers($number1, $number2); // modifies numbers    echo $number1;   echo $number2; //shows modified numbers ?>  <!-- stuff -->  <?php   function modifynumbers(&$number1, &$number2) {     $number1++;     $number2--;   } ?>