str replace for replacing str

<?php
$arr = array("ram","shyam","sita","gita");
print_r(str_replace("shyam","ramesh",$arr,$i));
echo "Replacements: $i";
?>

The output of the code above will be:

Array
(
[0] =>ram
[1] =>ramesh
[2] =>sita
[3] =>gita
)
Replacements: 1