php function array_sum() that returns the sum of all values ​​in the array

<?php
$a=array(5,15,25);
echo array_sum($a);
?>

array_sum(array)

<?php
$a=array("a"=>52.2,"b"=>13.7,"c"=>0.9);
echo array_sum($a);
?>

<?php 
$a=array(0=>"5",1=>"15",2=>"25"); 
echo array_sum($a); 
?>

<?php 
$a=array(0=>5,1=>15,2=>25); 
echo array_sum($a); 
?>

<?php 
$a=array(0=>5,1=>15.5,2=>25); 
echo array_sum($a); 
?>

45.5

<?php 
$a=array(0=>5,1=>"15s",2=>25); 
echo array_sum($a); 
?>

<?php 
$a=array(0=>5,1=>"s15s",2=>25); 
echo array_sum($a); 
?>

30